Anomalous enhanced emission from PbS quantum dots on a photonic-crystal microcavity

doi:10.1364/JOSAB.28.001365

Anomalous enhanced emission from PbS quantum dots on a photonic-crystal microcavity

Ting Shan Luk, Shisheng Xiong, Weng W. Chow, Xiaoyu Miao, Ganapathi Subramania, Paul J. Resnick, Arthur J. Fischer, and Jeffrey C. Brinker »View Author Affiliations

JOSA B, Vol. 28, Issue 6, pp. 1365-1373 (2011)
http://dx.doi.org/10.1364/JOSAB.28.001365

View Full Text Article

Acrobat PDF (840 KB)

Journal Search
Article Lookup

Article Tools

Citations

Alert me when this article is cited
Export Citation/Save

Article Navigation

▸ Article Outline
– Abstract
1. INTRODUCTION
2. FABRICATION OF PHOTONIC CRYSTALS AND CLOSE-PACKED MONOLAYER POLYMER FILMS
3. OPTICAL MEASUREMENTS
4. DISCUSSION AND CONCLUSION
– References and links

Article Tools
Full Text
Article Info
References
Cited By
Figures
Metrics
Download PDF

Viewing Equations in the
HTML Article

Optimal Viewing Recommendations

Full Text
Article Info
References (65)
Cited By
Figures (8)
Metrics

Abstract

We report up to 75 times enhancement in emission from lithographically produced photonic crystals with postprocessing close-packed colloidal quantum-dot incorporation. In our analysis, we use the emission from a close-packed free-standing film as a reference. After discounting the angular redistribution effect, our analysis shows that the observed enhancement is larger than the combined effects of Purcell enhancement and dielectric enhancement with the microscopic local field. The additional enhancement mechanisms, which are consistent with all our observations, are thought to be spectral diffusion mediated by phonons and local polarization fluctuations that allow off-resonant excitons to emit at the cavity wavelengths.

1. INTRODUCTION

Quantum-dot (QD) emission in a microcavity has been intensively investigated recently due to rapid advances in achieving simultaneously high Q and small mode volume cavities [1

K. J. Vahala, “Optical microcavities,” Nature 424, 839–846 (2003). [CrossRef] [PubMed]

]. Semiconductor QD emitters in microcavities have the potential to realize practical devices such as zero threshold lasers [2

J. Wiersig, C. Gies, F. Jahnke, M. Aszmann, T. Berstermann, M. Bayer, C. Kistner, S. Reitzenstein, C. Schneider, S. Hofling, A. Forchel, C. Kruse, J. Kalden, and D. Hommel, “Direct observation of correlations between individual photon emission events of a microcavity laser,” Nature 460, 245–249 (2009). [CrossRef] [PubMed]

] and single and entangled photon sources [3

M. Pelton, C. Santori, J. Vuckovic, B. Zhang, G. S. Solomon, J. Plant, and Y. Yamamoto, “Efficient source of single photons: a single quantum dot in a micropost microcavity,” Phys. Rev. Lett. 89, 233602 (2002). [CrossRef] [PubMed]

, 4

C. Santori, D. Fattal, J. Vuckovic, G. S. Solomon, and Y. Yamamoto, “Indistinguishable photons from a single-photon device,” Nature 419, 594–597 (2002). [CrossRef] [PubMed]

], as well as advances in quantum optics research [5

B. Lounis and M. Orrit, “Single-photon sources,” Rep. Prog. Phys. 68, 1129–1179 (2005). [CrossRef]

, 6

G. Khitrova, H. M. Gibbs, M. Kira, S. W. Koch, and A. Scherer, “Vacuum Rabi splitting in semiconductors,” Nat. Phys. 2, 81–90 (2006). [CrossRef]

, 7

A. J. Shields, “Semiconductor quantum light sources,” Nat. Photon. 1, 215–223 (2007). [CrossRef]

, 8

P. Michler, A. Imamoglu, M. D. Mason, P. J. Carson, G. F. Strouse, and S. K. Buratto, “Quantum correlation among photons from a single quantum dot at room temperature,” Nature 406, 968–970 (2000). [CrossRef] [PubMed]

]. In addition, the ability to enhance the emission rate by photonic density of states control [9

M. Boroditsky, R. Vrijen, T. F. Krauss, R. Coccioli, R. Bhat, and E. Yablonovitch, “Spontaneous emission extraction and Purcell enhancement from thin-film 2-D photonic crystals,” J. Lightwave Technol. 17, 2096–2112 (1999). [CrossRef]

] is also important to silicon photonics [10

T. Tanabe, K. Nishiguchi, E. Kuramochi, and M. Notomi, “Low power and fast electro-optic silicon modulator with lateral p-i-n embedded photonic crystal nanocavity,” Opt. Express 17, 22505–22513 (2009). [CrossRef]

], solid-state lighting [11

J. M. Phillips, P. E. Burrows, R. F. Daves, J. A. Simmons, G. G. Malliaras, F. So, J. A. Misewich, A. V. Nurmikko, and D. L. Smith, “Basic research needs for solid-state lighting,” Basic Energy Sciences report (U.S. Department of Energy, 2006), http://www.sc.doe.gov/bes/reports/files/SSL_rpt.pdf.

, 12

M. Ji, S. Park, S. T. Connor, T. Mokari, Y. Cui, and K. J. Gaffney, “Efficient multiple exciton generation observed in colloidal PbSe quantum dots with temporally and spectrally resolved intraband excitation,” Nano Lett. 9, 1217–1222 (2009). [CrossRef] [PubMed]

], and solar cell applications [12

, 13

T. Tiedje, E. Yablonovitch, G. D. Cody, and B. G. Brooks, “Limiting efficiency of silicon solar cells,” IEEE Trans. Electron Devices ED-31, 711–716 (1984). [CrossRef]

In the case of good emitters, such as InAs QDs at low temperatures, in which the total dephasing and the radiative linewidth are both much smaller than the cavity linewidth, large enhancement in spontaneous emission have been clearly demonstrated in the weak coupling regime [14

A. Kress, F. Hofbauer, N. Reinelt, M. Kaniber, H. J. Krenner, R. Meyer, G. Bohm, and J. J. Finley, “Manipulation of the spontaneous emission dynamics of quantum dots in two-dimensional photonic crystals,” Phys. Rev. B 71, 241304(R) (2005). [CrossRef]

, 15

T. Lund-Hansen, S. Stobbe, B. Julsgaard, H. Thyrrestrup, T. Sunner, M. Kamp, A. Forchel, and P. Lodahl, “Experimental realization of highly efficient broadband coupling of single quantum dots to a photonic crystal waveguide,” Phys. Rev. Lett. 101, 113903 (2008). [CrossRef] [PubMed]

, 16

M. Makarova, J. Vuckovic, H. Sanda, and Y. Nishi, “Silicon-based photonic crystal nanocavity light emitters,” Appl. Phys. Lett. 89, 221101 (2006). [CrossRef]

]. Recently, strong coupling behavior has also been demonstrated [17

M. Nomura, N. Kumagai, S. Iwamoto, Y. Ota, and Y. Arakawa, “Photonic crystal nanocavity laser with a single quantum dot gain,” Opt. Express 17, 15975–15982 (2009). [CrossRef] [PubMed]

, 18

I. Fushman, D. Englund, A. Faraon, N. Stoltz, P. Petroff, and J. Vuckovic, “Controlled phase shifts with a single quantum dot,” Science 320, 769–772 (2008). [CrossRef] [PubMed]

, 19

A. Faraon, I. Fushman, D. Englund, N. Stoltz, P. Petroff, and J. Vuckovic, “Coherent generation of non-classical light on a chip via photon-induced tunnelling and blockade,” Nature Phys. 4, 859–863 (2008). [CrossRef]

]. However, current understanding of nonideal or “bad emitter” systems in which the dephasing width is much larger than the radiative width and the cavity linewidth, is less clear [20

I. Fushman, D. Englund, and J. Vuckovic, “Coupling of PbS quantum dots to photonic crystal cavities at room temperature,” Appl. Phys. Lett. 87, 241102 (2005). [CrossRef]

, 21

M. Fujita, Y. Tanaka, and S. Noda, “Light emission from silicon in photonic crystal nanocavity,” IEEE J. Sel. Top. Quantum Electron. 14, 1090–1097 (2008). [CrossRef]

, 22

Z. Wu, Z. Mi, P. Bhattacharya, T. Zhu, and J. Xu, “Enhanced spontaneous emission at $1.55 μm$ from colloidal PbSe quantum dots in a Si photonic crystal microcavity,” Appl. Phys. Lett. 90, 171105 (2007). [CrossRef]

, 23

M. Makarova, V. Sih, J. Warga, R. Li, L. Dal Negro, and J. Vuckovic, “Enhanced light emission in photonic crystal nanocavities with erbium-doped silicon nanocrystals,” Appl. Phys. Lett. 92, 161107 (2008). [CrossRef]

, 24

A. G. Pattantyus-Abraham, H. Qiao, J. Shan, K. A. Abel, T.-S. Wang, F. C. J. M. van Veggel, and J. F. Young, “Site-selective optical coupling of PbSe nanocrystals to Si-based photonic crystal microcavities,” Nano Lett. 9, 2849–2854 (2009). [CrossRef] [PubMed]

, 25

J. Yang, J. Heo, T. Zhu, J. Xu, J. Topolancik, F. Vollmer, R. Ilic, and P. Bhattacharya, “Enhanced photoluminescence from embedded PbSe colloidal quantum dots in silicon-based random photonic crystal microcavities,” Appl. Phys. Lett. 92, 261110 (2008). [CrossRef]

, 26

Y. Gong, M. Makarova, S. Yerci, R. Li, M. J. Stevens, B. Baek, S. W. Nam, R. H. Hadfield, S. N. Dorenbos, V. Zwiller, J. Vuckovic, and L. Dal Negro, “Linewidth narrowing and Purcell enhancement in photonic crystal cavitieson an Er-doped silicon nitride platform,” Opt. Express 18, 2601–2612 (2010). [CrossRef] [PubMed]

]. Examples of bad emitters are colloidal infrared PbS and PbSe QDs, Si nanocrystals, and

{Er}^{3 +}

ions in

{SiO}_{2}

or silicon nitride. According to several theoretical studies [27

A. Meldrum, P. Bianucci, and F. Marsiglio, “Modification of ensemble emission rates and luminescence spectra for inhomogeneously broadened distributions of quantum dots coupled to optical microcavities,” Opt. Express 18, 10230–10246 (2010). [CrossRef] [PubMed]

, 28

H. Y. Ryu and M. Notomi, “Enhancement of spontaneous emission from the resonant modes of a photonic crystal slab single-defect cavity,” Opt. Lett. 28, 2390–2392 (2003). [CrossRef] [PubMed]

, 29

Y. Xu, R. K. Lee, and A. Yariv, “Finite-difference time-domain analysis of spontaneous emission in a microdisk cavity,” Phys. Rev. A 61, 033808 (2000). [CrossRef]

], for emitter systems like PbS and PbSe QDs, the Purcell enhancement is negligible and is independent of the cavity Q factor but, rather, is determined by the emitter Q factor. Experimentally reported enhancement factors from “bad emitters” have a large amount of variation. A Purcell enhancement factor of 30 was reported by spin coating colloidal PbS QDs embedded in polymethyl methacrylate on a photonic-crystal microcavity with

Q = 400

[20

I. Fushman, D. Englund, and J. Vuckovic, “Coupling of PbS quantum dots to photonic crystal cavities at room temperature,” Appl. Phys. Lett. 87, 241102 (2005). [CrossRef]

]. An enhancement factor of 10 has also been reported with a cavity Q of 3000 [24

] using selective chemical adsorption activated by atomic force microscope (AFM) nanopatterning. In another case, PbS QDs attached to the cavity by soaking yielded an enhancement factor of 35 from a cavity with

Q = 775

[22

]. For

{Er}^{3 +}

ions in silicon nitride, a room temperature enhancement factor of 1.4 was reported from a cavity with

Q = 6000

[30

]. None of these studies has demonstrated a linear dependence of enhancement factor to Q factor. In these PbS studies, the reported enhancement factor mechanism was attributed to the Purcell effect. In addition, for all these studies except for the AFM patterning case, the emitters are randomly distributed within the film and, therefore, the emitter distances from the surface of the photonic crystal are not well defined.

In this study, we measure the enhanced emission from PbS QDs with well-controlled dot-cavity locations with respect to a free-standing monolayer of close-packed QDs, which enables a stable reference with known angular distribution. A

20 - 50 nm

thick polymer film supporting a monolayer of close- packed PbS QDs can be deposited onto the surface of a photonic-crystal microcavity where these QDs are located at the interface between the polymer and the photonic-crystal [31

S. Xiong, X. Miao, J. Spencer, C. Khripin, T. S. Luk, and C. J. Brinker, “Integration of a close-packed quantum dot monolayer with a photonic-crystal cavity via interfacial self-assembly and transfer,” Small 6, 2126–2129 (2010). [CrossRef] [PubMed]

]. In this case, the surface of the cavity is uniformly covered with QDs and, therefore, there are an equal number of dots on the node and antinode regions of the cavity. The highest Q factor achieved with this technique is greater than 8000. After studying a large number of cavity-emitter structures, our measurements show no clear linear relationship between the enhancement factor and the cavity Q, suggesting that the enhancement mechanism is not dominated by the Purcell effect. Furthermore, we observe an enhancement factor larger than expected for the combined effects of Purcell, dielectric, and local field enhancements. We will present our experimental results and discuss possible enhancement mechanisms that could play a role for QDs in a microcavity.

2. FABRICATION OF PHOTONIC CRYSTALS AND CLOSE-PACKED MONOLAYER POLYMER FILMS

For photonic-crystal and microcavity fabrication, the starting material is a

150 mm

diameter silicon-on-insulator (SOI) wafer with a

250 nm

thick silicon device layer with a

3 μm

thick buried-oxide (BOx) layer. The pattern is a triangular lattice with lattice constant in the

Γ - K

direction of

a = 415 nm

and a hole diameter of

240 nm

. A cavity is created in the photonic-crystal lattice by three missing air holes (L3) as shown in Figs. 1a, 1b, 1c. The cavity has the end-hole positions shifted away from the cavity by nominal values of

0.18 a

0.025 a

, and

0.18 a

, as in the design by Akahane et al. [32

Y. Akahane, T. Asano, B. S. Song, and S. Noda, “High-Q photonic nanocavity in a two-dimensional photonic crystal,” Nature 425 (2003). [CrossRef] [PubMed]

]. Devices fabricated thereby have 100–300 holes in the

Γ - K

direction with a waveguide along this direction and 15 holes in the

Γ - X

direction. We use commercially available, mass- production semiconductor processing tools throughout the fabrication process. A waveguide is also fabricated that can be used to couple an external source into the microcavity. The coupling strength is controlled by the number of holes between the waveguide and the cavity. In particular, we will discuss results associated with the

1.0 W_{1}

waveguide defect, which is a row of missing holes.

All lithography was performed on an ASML PAS 5500 Step-and-Scan system, and all dry etching was performed with an Applied Materials Centura platform tool. The first lithographic layer defines the photonic crystal by patterning the

240 nm

diameter holes in the photoresist. This pattern is transferred into the device layer using reactive ion etching (RIE), optimized for straight vertical sidewalls. A second mask level was used to etch the substrate on either side of the device for optical access. A deep RIE (DRIE) process was used to create roughly

80 μm

deep grooves into the silicon to provide optical coupling of the lensed fiber to the waveguides. To protect the photonic crystal that had been etched into the device layer, an

850 nm

polysilicon film was deposited on top of a

2 μm

thick oxide film and then patterned with a photoresist mask. The polysilicon hard mask was used for the oxide etch steps because relatively thick oxide films were employed (

2 μm

hard mask,

3 μm

BOx). The oxide film served as a hard mask for the DRIE Si etch. During the BOx etch, the photoresist mask is consumed and the polysilicon hard mask is used to define the pattern. During the DRIE handle etch, the polysilicon mask is also consumed so that the underlying

2 μm

oxide film now acts as the mask to protect the silicon photonic-crystal device. Finally, hydrofluoric acid was used to strip the remaining oxide hard mask, as well as to undercut the SOI BOx below the lattice. A timed etch was used so that the oxide was stripped below the lattice to produce an air-clad photonic crystal, but sufficient oxide remained at the edge of the device to anchor the structure to the substrate. Figure 1a shows scanning electron microscope (SEM) images of a fabricated photonic-crystal device.

A monolayer of close-packed PbS QDs (purchased from Evident Technologies) was created using evaporation- induced nanoparticles/polymer self-assembly [33

J. Pang, S. Xiong, F. Jaeckel, Z. Sun, D. Dunphy, and C. J. Brinker, “Free-standing, patternable nanoparticle/polymer monolayer arrays formed by evaporation induced self-assembly at a fluid interface,” J. Am. Chem. Soc. 130, 3284–3285 (2008). [CrossRef] [PubMed]

] at a fluid interface, followed by monolayer transfer, as was recently reported [31

]. Because the monolayer has a high modulus, it remains suspended over air holes without adhering to the side walls. A suspended film with a sufficiently large area is also present in certain parts of the chip to enable free-film photoluminescence (PL) measurement, which is used as a reference signal. A transmission electron microscope (TEM) image of the QD film transferred onto a holey carbon grid is shown in the inset of Fig. 1d. The close packing gives a QD density of

10^{4} {μm}^{- 2}

, which is over 2 orders of magnitude higher than that of the typical Stranski–Krastanov growth method. The density and uniformity are sufficiently high to relax the requirement of matching QD locations to the antinode region of the cavity mode. Moreover, colloidal QDs provide greater integration flexibility with photonic crystals and nanostructured photonic materials. Using this approach, incorporation of QDs occurs during postprocessing, under ambient conditions using self-assembly of ligand functionalized QDs [24

, 33

, 34

H. Fan, K. Yang, D. M. Boye, T. Sigmon, K. J. Malloy, H. Xu, G. P. López, and C. J. Brinker, “Self-assembly of ordered, robust, three-dimensional gold nanocrystal/silica arrays,” Science 304, 567–571 (2004). [CrossRef] [PubMed]

To measure the PL of the excited QDs, we used a standard micro-PL setup where the excitation source and PL signal are focused and collected through a 0.65 NA Mitutoyo

50 \times

NIR HR microscope objective. This objective has a collection efficiency of 42% of the upper hemisphere. The field of view of the detection optics has about a

15 μm

diameter. The excitation source is a cw 830 or

904 nm

diode laser delivered by a single-mode

5.6 μm

core fiber collimated to match the entrance pupil of the objective. We have not noticed any significant difference in the enhancement factor when switching between these two laser sources. However, the

904 nm

laser appears to have a smaller photobleaching effect. A diffraction-limited spot size of

1.6 μm

1 / e^{2}

diameter is produced on the sample in the presence of a

175 μm

thick coverslip. The out-of-plane PL is collected by the same objective and coupled to a 0.3 or

0.5 m

imaging spectrometer through a

50 μm

diameter multimode fiber capable of achieving a spectral resolution of 0.4 and

0.1 nm

, respectively. An OMAV InGaAs array detector is used to detect spectrally dispersed emission.

3. OPTICAL MEASUREMENTS

3A. Spectroscopy of Microcavity Resonances

Emission comes mostly from the radiative recombination of ground electron and hole states, involving states populated via collisional relaxation from higher lying levels on a picosecond time scale [35

R. D. Schaller, J. M. Pietryga, S. V. Goupalov, M. A. Petruska, S. A. Ivanov, and V. I. Klimov, “Breaking the phonon bottleneck in semiconductor nanocrystals via multiphonon emission induced by intrinsic nonadiabatic interactions,” Phys. Rev. Lett. 95, 196401 (2005). [CrossRef] [PubMed]

]. The fact that the PL signal has no dependence on the excitation polarization is consistent with this pump relaxation process [36

J. M. An, M. Califano, A. Franceschetti, and A. Zunger, “Excited-state relaxation in PbSe quantum dots,” J. Chem. Phys. 128, 164720 (2008). [CrossRef] [PubMed]

]. However, the PL from the cavity resonance is highly polarized and is present only when the QDs on the cavity are excited. The wavelengths of the resonances are expected to be slightly different from sample to sample due to variation in the polymer film thickness, but their relative positions are very reproducible and in agreement with finite- difference time-domain (FDTD) calculations. We have used both poly-3-hexylthiophene (P3HT) and polystyrene (PS) polymers for the deposition and the difference in performance turned out to be relatively minor. A typical emission spectrum is shown in Fig. 2. The highest Q factor observed is from the

E_{y} 3

resonance with a Q factor greater than 8000 using PS as the polymer matrix material. The broad background emission is from QDs that are either not coupled to the cavity or are outside the cavity region excited by the laser. This broad background emission is very similar to the one obtained from a free-standing film (free-film). The weak feature at

1560 nm

for the

E_{x}

polarization is the

1.1 W_{1}

waveguide mode probably excited due to imperfect placement of the excitation spot. The other small features on the short wavelength side of the

E_{x} 1

resonance are hybridized modes caused by the coupling between the waveguide and the cavity.

For calculations of the photonic-crystal band structure, wavelengths of microcavity resonances, and Q factors, we use the MIT Electromagnetic Equation Propagation simulation environment [37

J. D. Joannopoulos, S. G. Johnson, J. N. Winn, and R. D. Meade, Photonic Crystals Molding the Flow of Light (Princeton Univ. Press, 2008).

]. The photonic-crystal structure including the polymer film is discretized into a three dimensional computational supercell of

20 \times 16 \times 20

periods. QD emission is simulated by an arrangement of multiple point current sources covering the waveguide and L3 cavity. For each point source, we use a Gaussian pulse centered at a reduced frequency of 0.273 (in unit of

c / 2 π a

) with a frequency spread of 0.05. Computation of the resonant frequencies together with their quality factors (Q) were performed with the harmonic inversion technique [38

V. A. Mandelshtam and H. S. Taylor, “Harmonic inversion of time signals and its applications,” J. Chem. Phys. 107, 6756–6769 (1997). [CrossRef]

]. Unlike the more commonly used Fourier transform, harmonic inversion describes the signal using an adaptive, finite length series of decaying and nondecaying sinusoids. The respective time series of the electric components for use with harmonic inversion were detected in the far field at 8 periods (computational unit cells) away from the sources. For the modal field calculations, we use a narrower (than QD emission) bandwidth for the point sources and tune the emission frequency around the neighborhood of the mode resonances. The modal patterns for

E_{x} 1

E_{y} 2

, and

E_{y} 3

are shown in Fig. 2. The quantitative agreement between theory and experiment is to within 1.5% in the resonant frequencies, as summarized in Table 1. For the

E_{x} 1

resonance, the measured Q factor is consistently higher than the calculated value. This may be due to the sensitivity of the cavity geometry; a very slight difference between input and actual cavity parameters may result in noticeable discrepancies. Examples of sensitive parameters include side-wall straightness and hole locations and diameters [32

Y. Akahane, T. Asano, B. S. Song, and S. Noda, “High-Q photonic nanocavity in a two-dimensional photonic crystal,” Nature 425 (2003). [CrossRef] [PubMed]

]. In addition, the integrated PL signal from the cavity-free patterned region is comparable to that obtained from a free-film, indicating that the PL signal is not being trapped or scattered outside the field of view of the detection system.

3B. Angular Distribution Measurements

In order to be able to determine the enhancement factor of the emission, it is necessary to normalize the cavity-resonance emission to the emission in the absence of cavity influences. We chose emission from a free-film as the reference because (1) the angular distribution from the film is guaranteed to obey the cosine law and (2) the PL intensity is very stable and uniform to within 20%. While the emission from the cavity-free patterned region is typically used as a reference in other work [21

M. Fujita, Y. Tanaka, and S. Noda, “Light emission from silicon in photonic crystal nanocavity,” IEEE J. Sel. Top. Quantum Electron. 14, 1090–1097 (2008). [CrossRef]

], we find this to be less reliable since the angular distribution is not necessarily a cosine law distribution and it can be affected by any buckling of the photonic-crystal membrane structure. The angular distributions of the free-film and cavity-free pattern region are shown in Fig. 3. Although the two distributions are somewhat similar, the uncertainty for the lattice emission is significantly larger. We have also found that the intensity from the cavity-free pattern region depends on the conformity of the film to the photonic-crystal surface.

The high resolution angular distribution of the cavity emission is difficult to measure because a large numerical aperture objective is needed to collect sufficient luminescence signal from the cavity. A coarse measure of the angular behaviors and collection efficiencies of the cavity resonances is possible using different numerical aperture focusing/collection objectives (shown in Fig. 4). The PL signals from

20 \times

and

10 \times

objectives are normalized to the collection efficiency value of 0.42 of the

50 \times

objective assuming a Lambertian source. To ensure this methodology is correct, we use the emission from a free-film as a test case and obtained the expected Lambertian behavior. From these measurements, we determined that the emission from the free-film and anchor (pattern-free) regions have very similar behavior. Both

E_{x} 1

and

E_{y} 2

resonances do not have their emission intensity peaked toward the normal direction due to significantly weaker signal than the cosine law distribution when the

10 \times

objective was used. These behaviors are consistent with the angular distributions obtained from numerical simulations shown in the insets of Figs. 4c, 4d. The key conclusion from these measurements is that none of these emissions has a very directional behavior, which can render gross errors in the enhancement factor estimates, which will be discussed in Subsections 3C, 3D.

3C. Enhanced Emission from the Fabry–Perot-Like Waveguide Resonances

Along the y direction, the waveguide can be viewed as a Fabry–Perot (FP) cavity bounded by two photonic lattice mirrors. The propagation vector of the FP cavity modes is along the y direction and, therefore, its electric field is along the x direction. This identification is consistent with the observed redshift of 10% of the resonance wavelength when the waveguide width is

1.1 W_{1}

instead of

1.0 W_{1}

. When the excitation source is focused on the waveguide, enhanced emission along x polarization is observed, as shown in Fig. 5. This emission is 5–8 times larger than that of the free-film. The background emission arises from the emitters not coupled to either the FP cavity resonance or to the photonic-crystal slab that emit into free space outside the sample. The excitation area is defined by the excitation spot diameter along the x direction and the width of the waveguide in the y direction; therefore, this area is comparable to the L3 microcavity. Correcting for excitation area that can couple to the waveguide (

area ratio = 6

), the emission rate is approximately 30–48 times larger than for a free-film even if one assumes a 100% collection efficiency [39

N.-V.-Q. Tran, S. Combrie, and A. De Rossi, “Directive emission from high-Q photonic crystal cavities through band folding,” Phys. Rev. B 79, 041101 (2009). [CrossRef]

]. No such distinct resonance from any waveguide is observed in the y polarization.

As mentioned before, the Purcell effect is small because of the low emitter Q. However, the dielectric enhancement mechanism does not depend on the Q factor of the emitter or the cavity Q. It is known that the presence of high refractive index material enhances the emission rate by a factor of n in a conventional macroscopic field correction [40

J.-Y. Zhang, X.-Y. Wang, and M. Xiao, “Modification of spontaneous emission from CdSe/CdS quantum dots in the presence of a semiconductor interface,” Opt. Lett. 27, 1253–1255 (2002). [CrossRef]

]. This arises from the fact that the vacuum field amplitude is reduced by a factor of n, but the free-space density of states increases as

n^{3}

. However, this enhancement mechanism does not include the local field effect. It was pointed out [41

M. E. Crenshaw, “The quantized field in a dielectric and application to the radiative decay of an embedded atom,” Phys. Lett. A 358, 438–442 (2006). [CrossRef]

, 42

K. Dolgaleva, R. W. Boyd, and P. W. Milonni, “Influence of local-field effects on the radiative lifetime of liquid suspensions of Nd:YAG nanoparticles,” J. Opt. Soc. Am. B 24, 516–521 (2007). [CrossRef]

, 43

P. R. Berman and P. W. Milonni, “Microscopic theory of modified spontaneous emission in a dielectric,” Phys. Rev. Lett. 92, 053601 (2004). [CrossRef] [PubMed]

] that the local field effect can introduce a significant correction to the macroscopic picture as the spontaneous emission rate of a dipole in a dielectric medium is given as

Γ_{D} = (n L^{2}) Γ_{vac}

, where

Γ_{D}

and

Γ_{vac}

are the decay rates of an emitter in a dielectric and vacuum, respectively, and L is the local field enhancement factor. There are many local field models: for the real-cavity model,

L = (3 n^{2}) / (2 n^{2} + 2)

[44

R. J. Glauber and M. Lewenstein, “Quantum optics of dielectric media,” Phys. Rev. A 43, 467–491 (1991). [CrossRef] [PubMed]

]; for the virtual cavity,

L = (n^{2} + 2) / 3

[42

, 45

H. A. Lorentz, Theory of Electrons and Its Applications to the Phenomena of Light and Radiant Heat (Stechert, 1916).

]; and from the Crenshaw model [41

M. E. Crenshaw, “The quantized field in a dielectric and application to the radiative decay of an embedded atom,” Phys. Lett. A 358, 438–442 (2006). [CrossRef]

, 46

M. E. Crenshaw and C. M. Bowden, “Effects of local fields on spontaneous emission in dielectric media,” Phys. Rev. Lett. 85, 1851–1854 (2000). [CrossRef] [PubMed]

L = ((n^{2} + 2) / 3 n)^{1 / 2}

. These enhancement factors are shown in Fig. 6. Experimental studies [42

, 47

E. He, H. Zheng, X. Zhang, and S. Qu, “Local-field effect on the fluorescence relaxation of $Tm 3 + : LaF 3$ nanocrystals immersed in liquid medium,” Luminescence 25, 66–70 (2010). [CrossRef] [CrossRef]

] in the index range of 1.3–1.7 have shown good agreement with the real-cavity model. Based on the real-cavity model for silicon, a significant dielectric enhancement factor

{EF}_{D} = n L^{2} = 7.3

is obtained.

We determined the dielectric enhancement factor for the free-film on a TEM grid to be 1.8 by comparing the emission of a free QD/polymer film. Since the QDs reside on the polymer–air interface, their emission into the polymer side is enhanced compared to the other side. This measurement provides an independent confirmation that the film is indeed thin enough that there are no trapped modes that could render a poor choice of reference. The measured value is slightly smaller than the expected 2.26 based on the real-cavity model. We believe this is due to the mean field effect because the film thickness is much smaller than the emission wavelength.

To determine the expected enhancement factor, we include the effects of the emitter area (A), enhanced absorption factor (

E_{A}

), dielectric enhancement (

{EF}_{D}

), Purcell cavity effect enhancement (

{EF}_{cav}

), coupling strength to the photonic-crystal cavity (β), coupling strength to free space from the cavity (

η_{FS}

), and collection efficiency (

η_{C}

). Therefore, we write the expected signal (S) as

S = A \cdot E_{A} \cdot {EF}_{D} \cdot {EF}_{cav} \cdot β \cdot η_{FS} \cdot η_{C}

, and the values in this expression for the free-film, waveguide, and

E_{x} 1

resonances are shown in Table 2.

An enhanced absorption factor

E_{A} = 1.3

takes into account that the QDs residing on the surface of Si experience another pass of the excitation beam because the reflectivity of silicon is about 30%. This value is consistent with the increase in the background signal from a cavity-free patterned region, as shown in Fig. 6. In addition, we have performed FDTD simulation to ensure there is no accidental enhancement due to surface mode or guided modes in the upper band of the photonic-crystal lattice [48

N. Ganesh, W. Zhang, P. C. Mathias, E. Chow, J. A. N. T. Soares, V. Malyarchuk, A. D. Smith, and B. T. Cunningham, “Enhanced fluorescence emission from quantum dots on a photonic crystal surface,” Nat. Nanotechnol. 2, 515–520 (2007). [CrossRef]

]. We assign the coupling efficiency from cavity to free space

η_{FS}

to 1 based on the numerical simulation studies of the dipole emitter in a general microcavity [49

J.-K. Hwang, H.-Y. Ryu, and Y.-H. Lee, “Spontaneous emission rate of an electric dipole in a general microcavity,” Phys. Rev. B 60, 4688–4695 (1999). [CrossRef]

, 50

S. Fan, P. R. Villeneuve, J. D. Joannopoulos, and E. F. Schubert, “High extraction efficiency of spontaneous emission from slabs of photonic crystals,” Phys. Rev. Lett. 78, 3294–3297 (1997). [CrossRef]

]. For the collection efficiency

η_{C}

, we assign the value of 1 to obtain the maximum enhancement effect from angular redistribution. A value less than 1 would result in a larger net enhancement effect. Together, the observed enhancement factor is still approximately 5 times below what we observed. It is worth noting that the amount of energy per unit area within the FP-like resonance peak is 85% of that emitted by the free-film into a

2 π

solid angle. This modified emission can be viewed as an act of spectral compression by the resonant cavity that directs the emission of QDs to the resonant wavelength. More discussion of this mechanism is in Section 4.

3D. Enhanced Emission from Microcavities

As discussed in Section 1, we use free-film emission as the reference to determine the enhancement factor. The enhancement factor is determined by taking the magnitude of the emission peak above the background and dividing by the free-film emission at the same wavelength. The enhancement factors for

E_{x} 1

E_{y} 1

E_{y} 2

, and

E_{y} 3

are shown in Fig. 7. The data shown are composed of measurements performed on different samples using both P3HT and PS polymers. Note that the expected linear dependence of the enhancement factor on Q due to the Purcell effect is absent, confirming that PbS belongs to the “bad emitter” class. The exact value of the homogeneous linewidth of PbS is still under debate [35

, 51

J. M. Harbold and F. W. Wise, “Photoluminescence spectroscopy of PbSe nanocrystals,” Phys. Rev. B 76, 125304 (2007). [CrossRef]

, 52

J. J. Peterson and T. D. Krauss, “Fluorescence spectroscopy of single lead sulfide quantum dots,” Nano Lett. 6, 510–514 (2006). [CrossRef] [PubMed]

, 53

L. Turyanska, A. Patane, M. Henini, B. Hennequin, and N. R. Thomas, “Temperature dependence of the photoluminescence emission from thiol-capped PbS quantum dots,” Appl. Phys. Lett. 90, 101913 (2007). [CrossRef]

]. From single QD measurements of PbS emitting at

800 nm

[52

J. J. Peterson and T. D. Krauss, “Fluorescence spectroscopy of single lead sulfide quantum dots,” Nano Lett. 6, 510–514 (2006). [CrossRef] [PubMed]

] and temperature-dependent measurements of PbS emission at

1100 nm

[53

], the homogeneous width was determined to be

90 - 100 meV

. This linewidth is significantly larger than the dephasing width of

1.2 meV

measured by pump–probe experiments in solution [35

], a value consistent with the relationship between the absorption cross section and the radiative lifetime. The dephasing width is known to increase significantly when QDs are cast in solid film form [22

]. Our own independent measurement confirms that the luminescence yield decreases by a factor of 10 when the quantum suspension film coalesces into a close-packed monolayer film on a water surface, resulting in a

12 meV

homogeneous linewidth. Even using this optimistic homogeneous width, we find the Purcell enhancement effect saturates at a value of 3.

As discussed in Subsection 3C, the dielectric enhancement including the local field effect is approximately 7.3. Again, as in the waveguide mode case, we assume a maximum value of 1 for the β coupling factor,

η_{FS}

free-space coupling efficiency, and

η_{C}

collection efficiency, yet the estimated emission strength is still a factor of 6 less than our observation.

A remaining concern is whether the observed emission enhancement is actually from amplified spontaneous emission. To address this question, we performed intensity-dependent studies and found three pieces of evidence to preclude this effect. First, with a change in excitation intensity from 10 to

10^{4} W / {cm}^{2}

, we did not find an increase in slope in the emission intensity versus excitation intensity, which would indicate a transition from spontaneous emission to amplified spontaneous emission (Fig. 8). In fact, they all show sublinear behavior, which fits very well to a power law dependence of the form

y = a x^{b}

, with

b = 0.75

for the

E_{x} 1

resonance at room temperature and

b = 0.82

for the

E_{y} 2

resonance at

105 K

. This sublinear behavior [54

V. I. Klimov, A. A. Mikhailovsky, S. Xu, A. Malko, J. A. Hollingsworth, C. A. Leatherdale, H. J. Eisler, and M. G. Bawendi, “Optical gain and stimulated emission in nanocrystal quantum dots,” Science 290, 314–317 (2000). [CrossRef] [PubMed]

] is commonly observed in colloidal QD PL and is believed to be associated with quenching processes [55

S. Liao, M. Dutta, D. Schonfeld, T. Yamanaka, and M. Stroscio, “Quantum dot blinking: relevance to physical limits for nanoscale optoelectronic device,” J. Comput. Electron. 7, 462–465 (2008). [CrossRef]

]. Second, the ratio between each emission peak and the background remains constant to within

< 20 %

over the same 3 orders of magnitude change in excitation intensities, indicating that there is no spectral redistribution upon change in pump intensity. Third, we observed neither linewidth narrowing nor any broadening for

E_{x} 1

E_{y} 2

, and

E_{y} 3

resonances with changes to pump power.

4. DISCUSSION AND CONCLUSION

We observed an approximate 75-fold enhancement in the emission from microcavity resonances and a 30-fold enhancement from FP-like waveguide modes. The lack of a linear relationship between the enhancement factor and cavity Q, and the fact that PbS QDs are “bad emitters,” indicate that the Purcell effect is not expected to be the dominant enhancement mechanism. After including the local field dielectric enhancement, the observed enhancement factor is still 5–6 times larger than expected. We believe the actual discrepancy is higher since we made generous estimates on the angular redistribution and collection efficiency. We are also able to rule out enhanced absorption based on the relative emission strength from the cavity-free patterned region and free-film using FDTD numerical simulations. Intensity dependent measurements of the emission and linewidth also exclude amplified spontaneous emission. Conclusive confirmation of this enhancement factor requires lifetime measurements of emitters in these structures, and presently, this measurement is not feasible. Nevertheless, the spectral energy content of the QD emission that couples to the FP-like resonance is 85% of the total emission from a free-film. This is very significant because it shows that one can reshape the broad emission spectrum in a very efficient way.

Using Fermi’s golden rule, saturation of the Purcell enhancement factor is based on the notion that the oscillator strength of the dipole is spread out over a large bandwidth and, therefore, the benefit of the high cavity Q and small volume can only impact this narrow portion of the homogeneous linewidth. However, this analysis does not take into consideration QD–QD interactions and interactions with the thermal bath. In the experiments reported here, the QDs in these close-packed films are separated from each other by a

1 - 2 nm

gap, which means that they are far from independent emitters. It is expected that these interactions cannot be ignored.

Anomalous enhancement in emission was also observed from Rhodamine 6G coupled to morphology-dependent optical modes in liquid droplets [56

M. D. Barnes, W. B. Whitten, and J. M. Ramsey, “Enhanced fluorescence yields through cavity quantum-electrodynamic effects in microdroplets,” J. Opt. Soc. Am. B 11, 1297–1304 (1994). [CrossRef]

]. The enhancement mechanism was interpreted as interaction of the excited molecule with surrounding solvent molecules causing the emission wavelength to wander dynamically, a phenomenon called spectral diffusion [57

A. D. Stein and M. D. Fayer, “Spectral diffusion in liquids,” J. Chem. Phys. 97, 2948–2962 (1992). [CrossRef]

]. The time it takes to wander through the homogeneous linewidth of Rhodamine is estimated to be comparable to its radiative lifetime of

3.6 ns

. The spectral diffusion effect is also prevalent in QD systems. Subnanosecond spectral diffusion time in a CdSe QD system was recently reported [58

G. Sallen, A. Tribu, T. Aichele, R. Andre, L. Besombes, C. Bougerol, M. Richard, S. Tatarenko, K. Kheng, and J. P. Poizat, “Subnanosecond spectral diffusion measurement using photon correlation,” Nat. Photon. 4, 696–699 (2010). [CrossRef]

]. This mechanism can effectively enlarge the spectral bandwidth that can contribute to the cavity emission; therefore, this mechanism is likely to contribute significantly an additional enhancement in emission in our experiment within a much longer radiative lifetime of

2 μs

Dipole–dipole interaction (Förster process) between excited–excited and excited–unexcited QDs is also expected to be strong due to their close proximity. Evidence of this process in a PbS quantum system was also reported [59

S. W. Clark, J. M. Harbold, and F. W. Wise, “Resonant energy transfer in PbS quantum dots,” J. Phys. Chem. C 111, 7302–7305 (2007). [CrossRef]

]. This mechanism can also cause excitons in the excited region to spread beyond the excitation region unless there is a mechanism to cause the donors to preferentially give their energy to acceptors inside the cavity. The cavity-enhanced Förster process has been reported in planar cavity geometries [60

P. Andrew and W. L. Barnes, “Förster energy transfer in an optical microcavity,” Science 290, 785–788 (2000). [CrossRef] [PubMed]

, 61

C. E. Finlayson, D. S. Ginger, and N. C. Greenham, “Enhanced Forster energy transfer in organic/inorganic bilayer optical microcavities,” Chem. Phys. Lett. 338, 83–87 (2001). [CrossRef]

]. However, this effect [62

G. S. Agarwal and S. D. Gupta, “Microcavity-induced modification of the dipole-dipole interaction,” Phys. Rev. A 57, 667–670 (1998). [CrossRef]

, 63

T. Kobayashi, Q. Zheng, and T. Sekiguchi, “Resonant dipole- dipole interaction in a cavity,” Phys. Rev. A 52, 2835–2846 (1995). [CrossRef] [PubMed]

] is much smaller than the observed enhancement effect in [60

P. Andrew and W. L. Barnes, “Förster energy transfer in an optical microcavity,” Science 290, 785–788 (2000). [CrossRef] [PubMed]

]. Since the typical time scale for Förster processes is of the order of nanoseconds, this is not expected to be as important as spectral diffusion.

Recently, phonon interaction has been shown to be important in coupling off-resonant QD excitation to emit at the cavity resonant frequency [64

A. Majundar, Y. Y. Gong, E. D. Kim, and J. Vuckovic, “Phonon mediated off-resonant quantum dot-cavity coupling,” arXiv:1012.3125v1 (2010).

]. Majumdar et al. in [64

A. Majundar, Y. Y. Gong, E. D. Kim, and J. Vuckovic, “Phonon mediated off-resonant quantum dot-cavity coupling,” arXiv:1012.3125v1 (2010).

] introduce phonon interaction to a two-level system coupled to an optical cavity and have shown significant enhanced emission at the cavity frequency due to several orders of magnitude increase in off-resonant coupling. This coupling mechanism allows nonresonant QDs to emit at the cavity wavelength and hence can increase the cavity emission beyond what Fermi’s golden rule can account for. The basic requirement for this mechanism to work is the presence of a dephasing mechanism. For the PbS system, the dephasing time is about

300 fs

in film form based on the

12 meV

linewidth we discussed. Because this coupling mechanism is not sensitive to the coupling strength between emitter and cavity, in other words, valid for both the strong and weak coupling regimes, this effect is expected to be present in our experiment and can provide an additional enhancement in emission [65

S. Ates, S. M. Ulrich, A. Ulhaq, S. Reitzenstein, A. Loffler, S. Hofling, A. Forchel, and P. Michler, “Non-resonant dot-cavity coupling and its potential for resonant single-quantum-dot spectroscopy,” Nat. Photon. 3, 724–728 (2009). [CrossRef]

In summary, the anomalous enhanced emission we observed may be due to spectral diffusion mediated by induced polarization of the environment and phonons, which enable a larger part of the homogeneous and inhomogeneous emitter linewidths to contribute to the cavity emissions. More experimental studies are planned to investigate these effects by controlling the particle spacing and temperature.

ACKNOWLEDGMENTS

The authors acknowledge fruitful discussions with Alon Gabbay, R. Kekatpure, and Mike Sinclair, numerical simulations from I. El-Kady, M. M. Su, B. G. Farfan, and M. R. Taha, and fabrication support from the staff at the Microelectronics Development Laboratory (MDL) at Sandia National Laboratories (SNL). Support for this work is from SNL’s Laboratory Directed Research Development (LDRD) program and by the U.S. Department of Energy (DOE) through the Office of Science, Office of Basic Energy Sciences (BES) for manuscript preparation and Energy Frontier Research Center (EFRC) for Solid-State Lighting Science for data analysis and Center for Integrated Nanotechnologies (CINT, national user facility) for experimental activities. SNL is a multiprogram laboratory operated by Sandia Corporation, a part of Lockheed-Martin Corporation, for the U.S. DOE under Contract No. DE-AC04-94AL85000.

References and links

1.	K. J. Vahala, “Optical microcavities,” Nature 424, 839–846 (2003). [CrossRef] [PubMed]
2.	J. Wiersig, C. Gies, F. Jahnke, M. Aszmann, T. Berstermann, M. Bayer, C. Kistner, S. Reitzenstein, C. Schneider, S. Hofling, A. Forchel, C. Kruse, J. Kalden, and D. Hommel, “Direct observation of correlations between individual photon emission events of a microcavity laser,” Nature 460, 245–249 (2009). [CrossRef] [PubMed]
3.	M. Pelton, C. Santori, J. Vuckovic, B. Zhang, G. S. Solomon, J. Plant, and Y. Yamamoto, “Efficient source of single photons: a single quantum dot in a micropost microcavity,” Phys. Rev. Lett. 89, 233602 (2002). [CrossRef] [PubMed]
4.	C. Santori, D. Fattal, J. Vuckovic, G. S. Solomon, and Y. Yamamoto, “Indistinguishable photons from a single-photon device,” Nature 419, 594–597 (2002). [CrossRef] [PubMed]
5.	B. Lounis and M. Orrit, “Single-photon sources,” Rep. Prog. Phys. 68, 1129–1179 (2005). [CrossRef]
6.	G. Khitrova, H. M. Gibbs, M. Kira, S. W. Koch, and A. Scherer, “Vacuum Rabi splitting in semiconductors,” Nat. Phys. 2, 81–90 (2006). [CrossRef]
7.	A. J. Shields, “Semiconductor quantum light sources,” Nat. Photon. 1, 215–223 (2007). [CrossRef]
8.	P. Michler, A. Imamoglu, M. D. Mason, P. J. Carson, G. F. Strouse, and S. K. Buratto, “Quantum correlation among photons from a single quantum dot at room temperature,” Nature 406, 968–970 (2000). [CrossRef] [PubMed]
9.	M. Boroditsky, R. Vrijen, T. F. Krauss, R. Coccioli, R. Bhat, and E. Yablonovitch, “Spontaneous emission extraction and Purcell enhancement from thin-film 2-D photonic crystals,” J. Lightwave Technol. 17, 2096–2112 (1999). [CrossRef]
10.	T. Tanabe, K. Nishiguchi, E. Kuramochi, and M. Notomi, “Low power and fast electro-optic silicon modulator with lateral p-i-n embedded photonic crystal nanocavity,” Opt. Express 17, 22505–22513 (2009). [CrossRef]
11.	J. M. Phillips, P. E. Burrows, R. F. Daves, J. A. Simmons, G. G. Malliaras, F. So, J. A. Misewich, A. V. Nurmikko, and D. L. Smith, “Basic research needs for solid-state lighting,” Basic Energy Sciences report (U.S. Department of Energy, 2006), http://www.sc.doe.gov/bes/reports/files/SSL_rpt.pdf.
12.	M. Ji, S. Park, S. T. Connor, T. Mokari, Y. Cui, and K. J. Gaffney, “Efficient multiple exciton generation observed in colloidal PbSe quantum dots with temporally and spectrally resolved intraband excitation,” Nano Lett. 9, 1217–1222 (2009). [CrossRef] [PubMed]
13.	T. Tiedje, E. Yablonovitch, G. D. Cody, and B. G. Brooks, “Limiting efficiency of silicon solar cells,” IEEE Trans. Electron Devices ED-31, 711–716 (1984). [CrossRef]
14.	A. Kress, F. Hofbauer, N. Reinelt, M. Kaniber, H. J. Krenner, R. Meyer, G. Bohm, and J. J. Finley, “Manipulation of the spontaneous emission dynamics of quantum dots in two-dimensional photonic crystals,” Phys. Rev. B 71, 241304(R) (2005). [CrossRef]
15.	T. Lund-Hansen, S. Stobbe, B. Julsgaard, H. Thyrrestrup, T. Sunner, M. Kamp, A. Forchel, and P. Lodahl, “Experimental realization of highly efficient broadband coupling of single quantum dots to a photonic crystal waveguide,” Phys. Rev. Lett. 101, 113903 (2008). [CrossRef] [PubMed]
16.	M. Makarova, J. Vuckovic, H. Sanda, and Y. Nishi, “Silicon-based photonic crystal nanocavity light emitters,” Appl. Phys. Lett. 89, 221101 (2006). [CrossRef]
17.	M. Nomura, N. Kumagai, S. Iwamoto, Y. Ota, and Y. Arakawa, “Photonic crystal nanocavity laser with a single quantum dot gain,” Opt. Express 17, 15975–15982 (2009). [CrossRef] [PubMed]
18.	I. Fushman, D. Englund, A. Faraon, N. Stoltz, P. Petroff, and J. Vuckovic, “Controlled phase shifts with a single quantum dot,” Science 320, 769–772 (2008). [CrossRef] [PubMed]
19.	A. Faraon, I. Fushman, D. Englund, N. Stoltz, P. Petroff, and J. Vuckovic, “Coherent generation of non-classical light on a chip via photon-induced tunnelling and blockade,” Nature Phys. 4, 859–863 (2008). [CrossRef]
20.	I. Fushman, D. Englund, and J. Vuckovic, “Coupling of PbS quantum dots to photonic crystal cavities at room temperature,” Appl. Phys. Lett. 87, 241102 (2005). [CrossRef]
21.	M. Fujita, Y. Tanaka, and S. Noda, “Light emission from silicon in photonic crystal nanocavity,” IEEE J. Sel. Top. Quantum Electron. 14, 1090–1097 (2008). [CrossRef]
22.	Z. Wu, Z. Mi, P. Bhattacharya, T. Zhu, and J. Xu, “Enhanced spontaneous emission at $1.55 μm$ from colloidal PbSe quantum dots in a Si photonic crystal microcavity,” Appl. Phys. Lett. 90, 171105 (2007). [CrossRef]
23.	M. Makarova, V. Sih, J. Warga, R. Li, L. Dal Negro, and J. Vuckovic, “Enhanced light emission in photonic crystal nanocavities with erbium-doped silicon nanocrystals,” Appl. Phys. Lett. 92, 161107 (2008). [CrossRef]
24.	A. G. Pattantyus-Abraham, H. Qiao, J. Shan, K. A. Abel, T.-S. Wang, F. C. J. M. van Veggel, and J. F. Young, “Site-selective optical coupling of PbSe nanocrystals to Si-based photonic crystal microcavities,” Nano Lett. 9, 2849–2854 (2009). [CrossRef] [PubMed]
25.	J. Yang, J. Heo, T. Zhu, J. Xu, J. Topolancik, F. Vollmer, R. Ilic, and P. Bhattacharya, “Enhanced photoluminescence from embedded PbSe colloidal quantum dots in silicon-based random photonic crystal microcavities,” Appl. Phys. Lett. 92, 261110 (2008). [CrossRef]
26.	Y. Gong, M. Makarova, S. Yerci, R. Li, M. J. Stevens, B. Baek, S. W. Nam, R. H. Hadfield, S. N. Dorenbos, V. Zwiller, J. Vuckovic, and L. Dal Negro, “Linewidth narrowing and Purcell enhancement in photonic crystal cavitieson an Er-doped silicon nitride platform,” Opt. Express 18, 2601–2612 (2010). [CrossRef] [PubMed]
27.	A. Meldrum, P. Bianucci, and F. Marsiglio, “Modification of ensemble emission rates and luminescence spectra for inhomogeneously broadened distributions of quantum dots coupled to optical microcavities,” Opt. Express 18, 10230–10246 (2010). [CrossRef] [PubMed]
28.	H. Y. Ryu and M. Notomi, “Enhancement of spontaneous emission from the resonant modes of a photonic crystal slab single-defect cavity,” Opt. Lett. 28, 2390–2392 (2003). [CrossRef] [PubMed]
29.	Y. Xu, R. K. Lee, and A. Yariv, “Finite-difference time-domain analysis of spontaneous emission in a microdisk cavity,” Phys. Rev. A 61, 033808 (2000). [CrossRef]
30.	M. Makarova, V. Sih, J. Warga, R. Li, L. Dal Negro, and J. Vuckovic, “Enhanced light emission in photonic crystal nanocavities with erbium-doped silicon nanocrystals,” Appl. Phys. Lett. 92, 161107 (2008). [CrossRef]
31.	S. Xiong, X. Miao, J. Spencer, C. Khripin, T. S. Luk, and C. J. Brinker, “Integration of a close-packed quantum dot monolayer with a photonic-crystal cavity via interfacial self-assembly and transfer,” Small 6, 2126–2129 (2010). [CrossRef] [PubMed]
32.	Y. Akahane, T. Asano, B. S. Song, and S. Noda, “High-Q photonic nanocavity in a two-dimensional photonic crystal,” Nature 425 (2003). [CrossRef] [PubMed]
33.	J. Pang, S. Xiong, F. Jaeckel, Z. Sun, D. Dunphy, and C. J. Brinker, “Free-standing, patternable nanoparticle/polymer monolayer arrays formed by evaporation induced self-assembly at a fluid interface,” J. Am. Chem. Soc. 130, 3284–3285 (2008). [CrossRef] [PubMed]
34.	H. Fan, K. Yang, D. M. Boye, T. Sigmon, K. J. Malloy, H. Xu, G. P. López, and C. J. Brinker, “Self-assembly of ordered, robust, three-dimensional gold nanocrystal/silica arrays,” Science 304, 567–571 (2004). [CrossRef] [PubMed]
35.	R. D. Schaller, J. M. Pietryga, S. V. Goupalov, M. A. Petruska, S. A. Ivanov, and V. I. Klimov, “Breaking the phonon bottleneck in semiconductor nanocrystals via multiphonon emission induced by intrinsic nonadiabatic interactions,” Phys. Rev. Lett. 95, 196401 (2005). [CrossRef] [PubMed]
36.	J. M. An, M. Califano, A. Franceschetti, and A. Zunger, “Excited-state relaxation in PbSe quantum dots,” J. Chem. Phys. 128, 164720 (2008). [CrossRef] [PubMed]
37.	J. D. Joannopoulos, S. G. Johnson, J. N. Winn, and R. D. Meade, Photonic Crystals Molding the Flow of Light (Princeton Univ. Press, 2008).
38.	V. A. Mandelshtam and H. S. Taylor, “Harmonic inversion of time signals and its applications,” J. Chem. Phys. 107, 6756–6769 (1997). [CrossRef]
39.	N.-V.-Q. Tran, S. Combrie, and A. De Rossi, “Directive emission from high-Q photonic crystal cavities through band folding,” Phys. Rev. B 79, 041101 (2009). [CrossRef]
40.	J.-Y. Zhang, X.-Y. Wang, and M. Xiao, “Modification of spontaneous emission from CdSe/CdS quantum dots in the presence of a semiconductor interface,” Opt. Lett. 27, 1253–1255 (2002). [CrossRef]
41.	M. E. Crenshaw, “The quantized field in a dielectric and application to the radiative decay of an embedded atom,” Phys. Lett. A 358, 438–442 (2006). [CrossRef]
42.	K. Dolgaleva, R. W. Boyd, and P. W. Milonni, “Influence of local-field effects on the radiative lifetime of liquid suspensions of Nd:YAG nanoparticles,” J. Opt. Soc. Am. B 24, 516–521 (2007). [CrossRef]
43.	P. R. Berman and P. W. Milonni, “Microscopic theory of modified spontaneous emission in a dielectric,” Phys. Rev. Lett. 92, 053601 (2004). [CrossRef] [PubMed]
44.	R. J. Glauber and M. Lewenstein, “Quantum optics of dielectric media,” Phys. Rev. A 43, 467–491 (1991). [CrossRef] [PubMed]
45.	H. A. Lorentz, Theory of Electrons and Its Applications to the Phenomena of Light and Radiant Heat (Stechert, 1916).
46.	M. E. Crenshaw and C. M. Bowden, “Effects of local fields on spontaneous emission in dielectric media,” Phys. Rev. Lett. 85, 1851–1854 (2000). [CrossRef] [PubMed]
47.	E. He, H. Zheng, X. Zhang, and S. Qu, “Local-field effect on the fluorescence relaxation of $Tm 3 + : LaF 3$ nanocrystals immersed in liquid medium,” Luminescence 25, 66–70 (2010). [CrossRef] [CrossRef]
48.	N. Ganesh, W. Zhang, P. C. Mathias, E. Chow, J. A. N. T. Soares, V. Malyarchuk, A. D. Smith, and B. T. Cunningham, “Enhanced fluorescence emission from quantum dots on a photonic crystal surface,” Nat. Nanotechnol. 2, 515–520 (2007). [CrossRef]
49.	J.-K. Hwang, H.-Y. Ryu, and Y.-H. Lee, “Spontaneous emission rate of an electric dipole in a general microcavity,” Phys. Rev. B 60, 4688–4695 (1999). [CrossRef]
50.	S. Fan, P. R. Villeneuve, J. D. Joannopoulos, and E. F. Schubert, “High extraction efficiency of spontaneous emission from slabs of photonic crystals,” Phys. Rev. Lett. 78, 3294–3297 (1997). [CrossRef]
51.	J. M. Harbold and F. W. Wise, “Photoluminescence spectroscopy of PbSe nanocrystals,” Phys. Rev. B 76, 125304 (2007). [CrossRef]
52.	J. J. Peterson and T. D. Krauss, “Fluorescence spectroscopy of single lead sulfide quantum dots,” Nano Lett. 6, 510–514 (2006). [CrossRef] [PubMed]
53.	L. Turyanska, A. Patane, M. Henini, B. Hennequin, and N. R. Thomas, “Temperature dependence of the photoluminescence emission from thiol-capped PbS quantum dots,” Appl. Phys. Lett. 90, 101913 (2007). [CrossRef]
54.	V. I. Klimov, A. A. Mikhailovsky, S. Xu, A. Malko, J. A. Hollingsworth, C. A. Leatherdale, H. J. Eisler, and M. G. Bawendi, “Optical gain and stimulated emission in nanocrystal quantum dots,” Science 290, 314–317 (2000). [CrossRef] [PubMed]
55.	S. Liao, M. Dutta, D. Schonfeld, T. Yamanaka, and M. Stroscio, “Quantum dot blinking: relevance to physical limits for nanoscale optoelectronic device,” J. Comput. Electron. 7, 462–465 (2008). [CrossRef]
56.	M. D. Barnes, W. B. Whitten, and J. M. Ramsey, “Enhanced fluorescence yields through cavity quantum-electrodynamic effects in microdroplets,” J. Opt. Soc. Am. B 11, 1297–1304 (1994). [CrossRef]
57.	A. D. Stein and M. D. Fayer, “Spectral diffusion in liquids,” J. Chem. Phys. 97, 2948–2962 (1992). [CrossRef]
58.	G. Sallen, A. Tribu, T. Aichele, R. Andre, L. Besombes, C. Bougerol, M. Richard, S. Tatarenko, K. Kheng, and J. P. Poizat, “Subnanosecond spectral diffusion measurement using photon correlation,” Nat. Photon. 4, 696–699 (2010). [CrossRef]
59.	S. W. Clark, J. M. Harbold, and F. W. Wise, “Resonant energy transfer in PbS quantum dots,” J. Phys. Chem. C 111, 7302–7305 (2007). [CrossRef]
60.	P. Andrew and W. L. Barnes, “Förster energy transfer in an optical microcavity,” Science 290, 785–788 (2000). [CrossRef] [PubMed]
61.	C. E. Finlayson, D. S. Ginger, and N. C. Greenham, “Enhanced Forster energy transfer in organic/inorganic bilayer optical microcavities,” Chem. Phys. Lett. 338, 83–87 (2001). [CrossRef]
62.	G. S. Agarwal and S. D. Gupta, “Microcavity-induced modification of the dipole-dipole interaction,” Phys. Rev. A 57, 667–670 (1998). [CrossRef]
63.	T. Kobayashi, Q. Zheng, and T. Sekiguchi, “Resonant dipole- dipole interaction in a cavity,” Phys. Rev. A 52, 2835–2846 (1995). [CrossRef] [PubMed]
64.	A. Majundar, Y. Y. Gong, E. D. Kim, and J. Vuckovic, “Phonon mediated off-resonant quantum dot-cavity coupling,” arXiv:1012.3125v1 (2010).
65.	S. Ates, S. M. Ulrich, A. Ulhaq, S. Reitzenstein, A. Loffler, S. Hofling, A. Forchel, and P. Michler, “Non-resonant dot-cavity coupling and its potential for resonant single-quantum-dot spectroscopy,” Nat. Photon. 3, 724–728 (2009). [CrossRef]

Table 1 Calculated and Measured Wavelengths and Q Factors of Cavity Resonances^{^a}

$ω a / 2 π c$	Identification	λ (expt/cal)	$Q_{\max}$ (expt/cal)	Experimental Uncertainty (nm)
$E \times WG$	$E_{x} 1$	1457.9/1455.04	600/416	$+ / - 3$
$E / / WG$	$E_{y} 1$	1399/1396	720/1214	$+ / - 10$
$E / / WG$	$E_{y} 2$	1512.44/1511.7	1257/2182	$+ / - 11$
$E / / WG$	$E_{y} 3$	1580.74/1582.7	8028/16108	$+ / - 9$

E / / WG

means the electric field polarization of the PL is parallel to the waveguide (WG) and

E \times WG

means the polarization of the PL is perpendicular to the WG.

Table 2 Estimated Enhanced Emission Factor Referenced to Free-Film

	Q	A (Excitation Spot Area)	${EF}_{A}$	${EF}_{D}$	${EF}_{cav}$	Coupling of QD Emission to Microcavity	Coupling of the Emission to Free Space	Collection Efficiency	Signal Strength (au)	Estimated	Measured Ratio (Normalized Area)
Free-film (.65NA)		1.00	1.00	1.80	n/a	n/a	1.00	0.42	0.8	1	1
$1.0 W_{1}$ resonances	100	0.16	1.30	7.30	2	0.32	1.00	1.00	4.7	6	30
$E_{x} 1$ resonance	500	0.16	1.30	7.30	3	0.32	1.00	1.00	9.1	12	75
$E_{y} 3$ resonance	2000	0.16	1.30	7.30	3	0.32	1.00	1.00	9.1	12	75

Fig. 1 (a) SEM image of a two-dimensional silicon membrane photonic-crystal device consisting of two L3 cavities and a waveguide supported with

{SiO}_{2}

anchors. The top left inset shows the top view of the holes on the silicon membrane. The lower right inset shows the side-wall profile of the holes. (b) Top SEM view of the L3 cavity created by three missing air holes. (c) SEM image of a cavity with polymer film on top. (d) TEM image of a monolayer of PbS in P3HT polymer. Lower left inset shows a free-film hanging by a corner feature of the photonic-crystal sample.

Fig. 2 Measured photoluminescence (PL) spectrum taken from the same L3 cavity with polarization parallel (

E_{x}

) and perpendicular (

E_{y}

) to the long axis of the cavity. The calculated modal patterns are shown next to resonance peaks. The inset shows the excitation spot size relative to the cavity.

Fig. 3 Measured angular distribution of photoluminescence from (a) a free-film and (b) a cavity-free patterned region with a monolayer of close-packed QDs. All data are normalized to the value of cos(

24 °

), which is the smallest angle the apparatus can measure.

Fig. 4 (a) Schematic drawing depicts the collection geometries of different numerical aperture (NA) objectives. The relative collection efficiency of the PL signals from

20 \times

and

10 \times

objectives are normalized to the Lambertian collection efficiency valued 0.42 for

50 \times

objective. (b) The relative collection efficiency behaviors of the PL from free-film, the anchor region, and the cosine law show minor deviation from the cosine law behavior. The relative collection efficiencies of (c)

E_{x} 1

and (d)

E_{y} 2

resonances using a

10 \times

objective are much smaller than cosine law behavior, indicating the emission is directed away from normal in agreement with simulation results (insets).

Fig. 5 Enhanced

E_{x}

emission from the FP-like resonance of the

1.0 W_{1}

waveguide (solid curve), free-film (dashed curve) and the Fano profile fit (dashed–dotted curve). Subtracting the peak signal from the background, the integrated signal corrected for the mode area in the peak is 85% of the total spectrally integrated free-film emission to the upper hemisphere. The inset shows the excitation region and the polarization direction.

Fig. 6 Combined enhancement from dielectric and from different localized field models.

Fig. 7 Measured enhancement factor of

E_{x} 1

E_{y} 1

E_{y} 2

, and

E_{y} 3

microcavity resonances with respect to the free-film. The enhancement factor is determined by the height of the resonance above the background emission divided by the emission of a free-film at the resonant frequency. The effect of excitation area to the cavity area is not included. Determination of the enhancement factors from higher Q cavities are unreliable due to poor signal-to-noise ratio of the reference signal since a higher resolution grating was required.

Fig. 8 Intensity dependent yield of

E_{x} 1

resonance at

295 K

(diamonds) and

E_{y} 2

resonance at

105 K

(squares), along with the power dependence fit to

y = a x^{b}

. The fit parameters and quality of fit are shown in the figure.

OCIS Codes
(230.0230) Optical devices : Optical devices
(300.2140) Spectroscopy : Emission
(140.3945) Lasers and laser optics : Microcavities
(350.4238) Other areas of optics : Nanophotonics and photonic crystals

ToC Category:
Lasers and Laser Optics

History
Original Manuscript: February 15, 2011
Manuscript Accepted: March 23, 2011
Published: May 9, 2011

Virtual Issues
Vol. 6, Iss. 7 Virtual Journal for Biomedical Optics

Citation
Ting Shan Luk, Shisheng Xiong, Weng W. Chow, Xiaoyu Miao, Ganapathi Subramania, Paul J. Resnick, Arthur J. Fischer, and Jeffrey C. Brinker, "Anomalous enhanced emission from PbS quantum dots on a photonic-crystal microcavity," J. Opt. Soc. Am. B 28, 1365-1373 (2011)
http://www.opticsinfobase.org/vjbo/abstract.cfm?URI=josab-28-6-1365

Sort: Author | Year | Journal | Reset

References

K. J. Vahala, “Optical microcavities,” Nature 424, 839–846(2003). [CrossRef] [PubMed]
J. Wiersig, C. Gies, F. Jahnke, M. Aszmann, T. Berstermann, M. Bayer, C. Kistner, S. Reitzenstein, C. Schneider, S. Hofling, A. Forchel, C. Kruse, J. Kalden, and D. Hommel, “Direct observation of correlations between individual photon emission events of a microcavity laser,” Nature 460, 245–249 (2009). [CrossRef] [PubMed]
M. Pelton, C. Santori, J. Vuckovic, B. Zhang, G. S. Solomon, J. Plant, and Y. Yamamoto, “Efficient source of single photons: a single quantum dot in a micropost microcavity,” Phys. Rev. Lett. 89, 233602 (2002). [CrossRef] [PubMed]
C. Santori, D. Fattal, J. Vuckovic, G. S. Solomon, and Y. Yamamoto, “Indistinguishable photons from a single-photon device,” Nature 419, 594–597 (2002). [CrossRef] [PubMed]
B. Lounis and M. Orrit, “Single-photon sources,” Rep. Prog. Phys. 68, 1129–1179 (2005). [CrossRef]
G. Khitrova, H. M. Gibbs, M. Kira, S. W. Koch, and A. Scherer, “Vacuum Rabi splitting in semiconductors,” Nat. Phys. 2, 81–90 (2006). [CrossRef]
A. J. Shields, “Semiconductor quantum light sources,” Nat. Photon. 1, 215–223 (2007). [CrossRef]
P. Michler, A. Imamoglu, M. D. Mason, P. J. Carson, G. F. Strouse, and S. K. Buratto, “Quantum correlation among photons from a single quantum dot at room temperature,” Nature 406, 968–970 (2000). [CrossRef] [PubMed]
M. Boroditsky, R. Vrijen, T. F. Krauss, R. Coccioli, R. Bhat, and E. Yablonovitch, “Spontaneous emission extraction and Purcell enhancement from thin-film 2-D photonic crystals,” J. Lightwave Technol. 17, 2096–2112 (1999). [CrossRef]
T. Tanabe, K. Nishiguchi, E. Kuramochi, and M. Notomi, “Low power and fast electro-optic silicon modulator with lateral p-i-n embedded photonic crystal nanocavity,” Opt. Express 17, 22505–22513 (2009). [CrossRef]
J. M. Phillips, P. E. Burrows, R. F. Daves, J. A. Simmons, G. G. Malliaras, F. So, J. A. Misewich, A. V. Nurmikko, and D. L. Smith, “Basic research needs for solid-state lighting,” Basic Energy Sciences report (U.S. Department of Energy, 2006), http://www.sc.doe.gov/bes/reports/files/SSL_rpt.pdf.
M. Ji, S. Park, S. T. Connor, T. Mokari, Y. Cui, and K. J. Gaffney, “Efficient multiple exciton generation observed in colloidal PbSe quantum dots with temporally and spectrally resolved intraband excitation,” Nano Lett. 9, 1217–1222 (2009). [CrossRef] [PubMed]
T. Tiedje, E. Yablonovitch, G. D. Cody, and B. G. Brooks, “Limiting efficiency of silicon solar cells,” IEEE Trans. Electron Devices ED-31, 711–716 (1984). [CrossRef]
A. Kress, F. Hofbauer, N. Reinelt, M. Kaniber, H. J. Krenner, R. Meyer, G. Bohm, and J. J. Finley, “Manipulation of the spontaneous emission dynamics of quantum dots in two-dimensional photonic crystals,” Phys. Rev. B 71, 241304(R) (2005). [CrossRef]
T. Lund-Hansen, S. Stobbe, B. Julsgaard, H. Thyrrestrup, T. Sunner, M. Kamp, A. Forchel, and P. Lodahl, “Experimental realization of highly efficient broadband coupling of single quantum dots to a photonic crystal waveguide,” Phys. Rev. Lett. 101, 113903 (2008). [CrossRef] [PubMed]
M. Makarova, J. Vuckovic, H. Sanda, and Y. Nishi, “Silicon-based photonic crystal nanocavity light emitters,” Appl. Phys. Lett. 89, 221101 (2006). [CrossRef]
M. Nomura, N. Kumagai, S. Iwamoto, Y. Ota, and Y. Arakawa, “Photonic crystal nanocavity laser with a single quantum dot gain,” Opt. Express 17, 15975–15982 (2009). [CrossRef] [PubMed]
I. Fushman, D. Englund, A. Faraon, N. Stoltz, P. Petroff, and J. Vuckovic, “Controlled phase shifts with a single quantum dot,” Science 320, 769–772 (2008). [CrossRef] [PubMed]
A. Faraon, I. Fushman, D. Englund, N. Stoltz, P. Petroff, and J. Vuckovic, “Coherent generation of non-classical light on a chip via photon-induced tunnelling and blockade,” Nature Phys. 4, 859–863 (2008). [CrossRef]
I. Fushman, D. Englund, and J. Vuckovic, “Coupling of PbS quantum dots to photonic crystal cavities at room temperature,” Appl. Phys. Lett. 87, 241102 (2005). [CrossRef]
M. Fujita, Y. Tanaka, and S. Noda, “Light emission from silicon in photonic crystal nanocavity,” IEEE J. Sel. Top. Quantum Electron. 14, 1090–1097 (2008). [CrossRef]
Z. Wu, Z. Mi, P. Bhattacharya, T. Zhu, and J. Xu, “Enhanced spontaneous emission at 1.55 μm from colloidal PbSe quantum dots in a Si photonic crystal microcavity,” Appl. Phys. Lett. 90, 171105 (2007). [CrossRef]
M. Makarova, V. Sih, J. Warga, R. Li, L. Dal Negro, and J. Vuckovic, “Enhanced light emission in photonic crystal nanocavities with erbium-doped silicon nanocrystals,” Appl. Phys. Lett. 92, 161107 (2008). [CrossRef]
A. G. Pattantyus-Abraham, H. Qiao, J. Shan, K. A. Abel, T.-S. Wang, F. C. J. M. van Veggel, and J. F. Young, “Site-selective optical coupling of PbSe nanocrystals to Si-based photonic crystal microcavities,” Nano Lett. 9, 2849–2854 (2009). [CrossRef] [PubMed]
J. Yang, J. Heo, T. Zhu, J. Xu, J. Topolancik, F. Vollmer, R. Ilic, and P. Bhattacharya, “Enhanced photoluminescence from embedded PbSe colloidal quantum dots in silicon-based random photonic crystal microcavities,” Appl. Phys. Lett. 92, 261110(2008). [CrossRef]
Y. Gong, M. Makarova, S. Yerci, R. Li, M. J. Stevens, B. Baek, S. W. Nam, R. H. Hadfield, S. N. Dorenbos, V. Zwiller, J. Vuckovic, and L. Dal Negro, “Linewidth narrowing and Purcell enhancement in photonic crystal cavitieson an Er-doped silicon nitride platform,” Opt. Express 18, 2601–2612 (2010). [CrossRef] [PubMed]
A. Meldrum, P. Bianucci, and F. Marsiglio, “Modification of ensemble emission rates and luminescence spectra for inhomogeneously broadened distributions of quantum dots coupled to optical microcavities,” Opt. Express 18, 10230–10246 (2010). [CrossRef] [PubMed]
H. Y. Ryu and M. Notomi, “Enhancement of spontaneous emission from the resonant modes of a photonic crystal slab single-defect cavity,” Opt. Lett. 28, 2390–2392 (2003). [CrossRef] [PubMed]
Y. Xu, R. K. Lee, and A. Yariv, “Finite-difference time-domain analysis of spontaneous emission in a microdisk cavity,” Phys. Rev. A 61, 033808 (2000). [CrossRef]
M. Makarova, V. Sih, J. Warga, R. Li, L. Dal Negro, and J. Vuckovic, “Enhanced light emission in photonic crystal nanocavities with erbium-doped silicon nanocrystals,” Appl. Phys. Lett. 92, 161107 (2008). [CrossRef]
S. Xiong, X. Miao, J. Spencer, C. Khripin, T. S. Luk, and C. J. Brinker, “Integration of a close-packed quantum dot monolayer with a photonic-crystal cavity via interfacial self-assembly and transfer,” Small 6, 2126–2129 (2010). [CrossRef] [PubMed]
Y. Akahane, T. Asano, B. S. Song, and S. Noda, “High-Q photonic nanocavity in a two-dimensional photonic crystal,” Nature 425 (2003). [CrossRef] [PubMed]
J. Pang, S. Xiong, F. Jaeckel, Z. Sun, D. Dunphy, and C. J. Brinker, “Free-standing, patternable nanoparticle/polymer monolayer arrays formed by evaporation induced self-assembly at a fluid interface,” J. Am. Chem. Soc. 130, 3284–3285 (2008). [CrossRef] [PubMed]
H. Fan, K. Yang, D. M. Boye, T. Sigmon, K. J. Malloy, H. Xu, G. P. López, and C. J. Brinker, “Self-assembly of ordered, robust, three-dimensional gold nanocrystal/silica arrays,” Science 304, 567–571 (2004). [CrossRef] [PubMed]
R. D. Schaller, J. M. Pietryga, S. V. Goupalov, M. A. Petruska, S. A. Ivanov, and V. I. Klimov, “Breaking the phonon bottleneck in semiconductor nanocrystals via multiphonon emission induced by intrinsic nonadiabatic interactions,” Phys. Rev. Lett. 95, 196401 (2005). [CrossRef] [PubMed]
J. M. An, M. Califano, A. Franceschetti, and A. Zunger, “Excited-state relaxation in PbSe quantum dots,” J. Chem. Phys. 128, 164720 (2008). [CrossRef] [PubMed]
J. D. Joannopoulos, S. G. Johnson, J. N. Winn, and R. D. Meade, Photonic Crystals Molding the Flow of Light (Princeton Univ. Press, 2008).
V. A. Mandelshtam and H. S. Taylor, “Harmonic inversion of time signals and its applications,” J. Chem. Phys. 107, 6756–6769(1997). [CrossRef]
N.-V.-Q. Tran, S. Combrie, and A. De Rossi, “Directive emission from high-Q photonic crystal cavities through band folding,” Phys. Rev. B 79, 041101 (2009). [CrossRef]
J.-Y. Zhang, X.-Y. Wang, and M. Xiao, “Modification of spontaneous emission from CdSe/CdS quantum dots in the presence of a semiconductor interface,” Opt. Lett. 27, 1253–1255 (2002). [CrossRef]
M. E. Crenshaw, “The quantized field in a dielectric and application to the radiative decay of an embedded atom,” Phys. Lett. A 358, 438–442 (2006). [CrossRef]
K. Dolgaleva, R. W. Boyd, and P. W. Milonni, “Influence of local-field effects on the radiative lifetime of liquid suspensions of Nd:YAG nanoparticles,” J. Opt. Soc. Am. B 24, 516–521(2007). [CrossRef]
P. R. Berman and P. W. Milonni, “Microscopic theory of modified spontaneous emission in a dielectric,” Phys. Rev. Lett. 92, 053601 (2004). [CrossRef] [PubMed]
R. J. Glauber and M. Lewenstein, “Quantum optics of dielectric media,” Phys. Rev. A 43, 467–491 (1991). [CrossRef] [PubMed]
H. A. Lorentz, Theory of Electrons and Its Applications to the Phenomena of Light and Radiant Heat (Stechert, 1916).
M. E. Crenshaw and C. M. Bowden, “Effects of local fields on spontaneous emission in dielectric media,” Phys. Rev. Lett. 85, 1851–1854 (2000). [CrossRef] [PubMed]
E. He, H. Zheng, X. Zhang, and S. Qu, “Local-field effect on the fluorescence relaxation of Tm3+:LaF3 nanocrystals immersed in liquid medium,” Luminescence 25, 66–70 (2010). [CrossRef]
N. Ganesh, W. Zhang, P. C. Mathias, E. Chow, J. A. N. T. Soares, V. Malyarchuk, A. D. Smith, and B. T. Cunningham, “Enhanced fluorescence emission from quantum dots on a photonic crystal surface,” Nat. Nanotechnol. 2, 515–520 (2007). [CrossRef]
J.-K. Hwang, H.-Y. Ryu, and Y.-H. Lee, “Spontaneous emission rate of an electric dipole in a general microcavity,” Phys. Rev. B 60, 4688–4695 (1999). [CrossRef]
S. Fan, P. R. Villeneuve, J. D. Joannopoulos, and E. F. Schubert, “High extraction efficiency of spontaneous emission from slabs of photonic crystals,” Phys. Rev. Lett. 78, 3294–3297 (1997). [CrossRef]
J. M. Harbold and F. W. Wise, “Photoluminescence spectroscopy of PbSe nanocrystals,” Phys. Rev. B 76, 125304 (2007). [CrossRef]
J. J. Peterson and T. D. Krauss, “Fluorescence spectroscopy of single lead sulfide quantum dots,” Nano Lett. 6, 510–514 (2006). [CrossRef] [PubMed]
L. Turyanska, A. Patane, M. Henini, B. Hennequin, and N. R. Thomas, “Temperature dependence of the photoluminescence emission from thiol-capped PbS quantum dots,” Appl. Phys. Lett. 90, 101913 (2007). [CrossRef]
V. I. Klimov, A. A. Mikhailovsky, S. Xu, A. Malko, J. A. Hollingsworth, C. A. Leatherdale, H. J. Eisler, and M. G. Bawendi, “Optical gain and stimulated emission in nanocrystal quantum dots,” Science 290, 314–317 (2000). [CrossRef] [PubMed]
S. Liao, M. Dutta, D. Schonfeld, T. Yamanaka, and M. Stroscio, “Quantum dot blinking: relevance to physical limits for nanoscale optoelectronic device,” J. Comput. Electron. 7, 462–465(2008). [CrossRef]
M. D. Barnes, W. B. Whitten, and J. M. Ramsey, “Enhanced fluorescence yields through cavity quantum-electrodynamic effects in microdroplets,” J. Opt. Soc. Am. B 11, 1297–1304 (1994). [CrossRef]
A. D. Stein and M. D. Fayer, “Spectral diffusion in liquids,” J. Chem. Phys. 97, 2948–2962 (1992). [CrossRef]
G. Sallen, A. Tribu, T. Aichele, R. Andre, L. Besombes, C. Bougerol, M. Richard, S. Tatarenko, K. Kheng, and J. P. Poizat, “Subnanosecond spectral diffusion measurement using photon correlation,” Nat. Photon. 4, 696–699 (2010). [CrossRef]
S. W. Clark, J. M. Harbold, and F. W. Wise, “Resonant energy transfer in PbS quantum dots,” J. Phys. Chem. C 111, 7302–7305 (2007). [CrossRef]
P. Andrew and W. L. Barnes, “Förster energy transfer in an optical microcavity,” Science 290, 785–788 (2000). [CrossRef] [PubMed]
C. E. Finlayson, D. S. Ginger, and N. C. Greenham, “Enhanced Forster energy transfer in organic/inorganic bilayer optical microcavities,” Chem. Phys. Lett. 338, 83–87 (2001). [CrossRef]
G. S. Agarwal and S. D. Gupta, “Microcavity-induced modification of the dipole-dipole interaction,” Phys. Rev. A 57, 667–670 (1998). [CrossRef]
T. Kobayashi, Q. Zheng, and T. Sekiguchi, “Resonant dipole-dipole interaction in a cavity,” Phys. Rev. A 52, 2835–2846(1995). [CrossRef] [PubMed]
A. Majundar, Y. Y. Gong, E. D. Kim, and J. Vuckovic, “Phonon mediated off-resonant quantum dot-cavity coupling,” arXiv:1012.3125v1 (2010).
S. Ates, S. M. Ulrich, A. Ulhaq, S. Reitzenstein, A. Loffler, S. Hofling, A. Forchel, and P. Michler, “Non-resonant dot-cavity coupling and its potential for resonant single-quantum-dot spectroscopy,” Nat. Photon. 3, 724–728 (2009). [CrossRef]

Abel, K. A.
Agarwal, G. S.
Aichele, T.
Akahane, Y.
An, J. M.
Andre, R.
Andrew, P.
Arakawa, Y.
Asano, T.
Aszmann, M.
Ates, S.
Baek, B.
Barnes, M. D.
Barnes, W. L.
Bawendi, M. G.
Bayer, M.
Berman, P. R.
Berstermann, T.
Besombes, L.
Bhat, R.
Bhattacharya, P.
Bianucci, P.
Bohm, G.
Boroditsky, M.
Bougerol, C.
Bowden, C. M.
Boyd, R. W.
Boye, D. M.
Brinker, C. J.
Brooks, B. G.
Buratto, S. K.
Burrows, P. E.
Califano, M.
Carson, P. J.
Chow, E.
Clark, S. W.
Coccioli, R.
Cody, G. D.
Combrie, S.
Connor, S. T.
Crenshaw, M. E.
Cui, Y.
Cunningham, B. T.
Dal Negro, L.
Daves, R. F.
De Rossi, A.
Dolgaleva, K.
Dorenbos, S. N.
Dunphy, D.
Dutta, M.
Eisler, H. J.
Englund, D.
Fan, H.
Fan, S.
Faraon, A.
Fattal, D.
Fayer, M. D.
Finlayson, C. E.
Finley, J. J.
Forchel, A.
Franceschetti, A.
Fujita, M.
Fushman, I.
Gaffney, K. J.
Ganesh, N.
Gibbs, H. M.
Gies, C.
Ginger, D. S.
Glauber, R. J.
Gong, Y.
Gong, Y. Y.
Goupalov, S. V.
Greenham, N. C.
Gupta, S. D.
Hadfield, R. H.
Harbold, J. M.
He, E.
Henini, M.
Hennequin, B.
Heo, J.
Hofbauer, F.
Hofling, S.
Hollingsworth, J. A.
Hommel, D.
Hwang, J.-K.
Ilic, R.
Imamoglu, A.
Ivanov, S. A.
Iwamoto, S.
Jaeckel, F.
Jahnke, F.
Ji, M.
Joannopoulos, J. D.
Johnson, S. G.
Julsgaard, B.
Kalden, J.
Kamp, M.
Kaniber, M.
Kheng, K.
Khitrova, G.
Khripin, C.
Kim, E. D.
Kira, M.
Kistner, C.
Klimov, V. I.
Kobayashi, T.
Koch, S. W.
Krauss, T. D.
Krauss, T. F.
Krenner, H. J.
Kress, A.
Kruse, C.
Kumagai, N.
Kuramochi, E.
Leatherdale, C. A.
Lee, R. K.
Lee, Y.-H.
Lewenstein, M.
Li, R.
Liao, S.
Lodahl, P.
Loffler, A.
López, G. P.
Lorentz, H. A.
Lounis, B.
Luk, T. S.
Lund-Hansen, T.
Majundar, A.
Makarova, M.
Malko, A.
Malliaras, G. G.
Malloy, K. J.
Malyarchuk, V.
Mandelshtam, V. A.
Marsiglio, F.
Mason, M. D.
Mathias, P. C.
Meade, R. D.
Meldrum, A.
Meyer, R.
Mi, Z.
Miao, X.
Michler, P.
Mikhailovsky, A. A.
Milonni, P. W.
Misewich, J. A.
Mokari, T.
Nam, S. W.
Nishi, Y.
Nishiguchi, K.
Noda, S.
Nomura, M.
Notomi, M.
Nurmikko, A. V.
Orrit, M.
Ota, Y.
Pang, J.
Park, S.
Patane, A.
Pattantyus-Abraham, A. G.
Pelton, M.
Peterson, J. J.
Petroff, P.
Petruska, M. A.
Phillips, J. M.
Pietryga, J. M.
Plant, J.
Poizat, J. P.
Qiao, H.
Qu, S.
Ramsey, J. M.
Reinelt, N.
Reitzenstein, S.
Richard, M.
Ryu, H. Y.
Ryu, H.-Y.
Sallen, G.
Sanda, H.
Santori, C.
Schaller, R. D.
Scherer, A.
Schneider, C.
Schonfeld, D.
Schubert, E. F.
Sekiguchi, T.
Shan, J.
Shields, A. J.
Sigmon, T.
Sih, V.
Simmons, J. A.
Smith, A. D.
Smith, D. L.
So, F.
Soares, J. A. N. T.
Solomon, G. S.
Song, B. S.
Spencer, J.
Stein, A. D.
Stevens, M. J.
Stobbe, S.
Stoltz, N.
Stroscio, M.
Strouse, G. F.
Sun, Z.
Sunner, T.
Tanabe, T.
Tanaka, Y.
Tatarenko, S.
Taylor, H. S.
Thomas, N. R.
Thyrrestrup, H.
Tiedje, T.
Topolancik, J.
Tran, N.-V.-Q.
Tribu, A.
Turyanska, L.
Ulhaq, A.
Ulrich, S. M.
Vahala, K. J.
van Veggel, F. C. J. M.
Villeneuve, P. R.
Vollmer, F.
Vrijen, R.
Vuckovic, J.
Wang, T.-S.
Wang, X.-Y.
Warga, J.
Whitten, W. B.
Wiersig, J.
Winn, J. N.
Wise, F. W.
Wu, Z.
Xiao, M.
Xiong, S.
Xu, H.
Xu, J.
Xu, S.
Xu, Y.
Yablonovitch, E.
Yamamoto, Y.
Yamanaka, T.
Yang, J.
Yang, K.
Yariv, A.
Yerci, S.
Young, J. F.
Zhang, B.
Zhang, J.-Y.
Zhang, W.
Zhang, X.
Zheng, H.
Zheng, Q.
Zhu, T.
Zunger, A.
Zwiller, V.

Appl. Phys. Lett.

M. Makarova, J. Vuckovic, H. Sanda, and Y. Nishi, “Silicon-based photonic crystal nanocavity light emitters,” Appl. Phys. Lett. 89, 221101 (2006). [CrossRef]
I. Fushman, D. Englund, and J. Vuckovic, “Coupling of PbS quantum dots to photonic crystal cavities at room temperature,” Appl. Phys. Lett. 87, 241102 (2005). [CrossRef]
J. Yang, J. Heo, T. Zhu, J. Xu, J. Topolancik, F. Vollmer, R. Ilic, and P. Bhattacharya, “Enhanced photoluminescence from embedded PbSe colloidal quantum dots in silicon-based random photonic crystal microcavities,” Appl. Phys. Lett. 92, 261110(2008). [CrossRef]
Z. Wu, Z. Mi, P. Bhattacharya, T. Zhu, and J. Xu, “Enhanced spontaneous emission at 1.55 μm from colloidal PbSe quantum dots in a Si photonic crystal microcavity,” Appl. Phys. Lett. 90, 171105 (2007). [CrossRef]
M. Makarova, V. Sih, J. Warga, R. Li, L. Dal Negro, and J. Vuckovic, “Enhanced light emission in photonic crystal nanocavities with erbium-doped silicon nanocrystals,” Appl. Phys. Lett. 92, 161107 (2008). [CrossRef]
M. Makarova, V. Sih, J. Warga, R. Li, L. Dal Negro, and J. Vuckovic, “Enhanced light emission in photonic crystal nanocavities with erbium-doped silicon nanocrystals,” Appl. Phys. Lett. 92, 161107 (2008). [CrossRef]
L. Turyanska, A. Patane, M. Henini, B. Hennequin, and N. R. Thomas, “Temperature dependence of the photoluminescence emission from thiol-capped PbS quantum dots,” Appl. Phys. Lett. 90, 101913 (2007). [CrossRef]

Chem. Phys. Lett.

C. E. Finlayson, D. S. Ginger, and N. C. Greenham, “Enhanced Forster energy transfer in organic/inorganic bilayer optical microcavities,” Chem. Phys. Lett. 338, 83–87 (2001). [CrossRef]

IEEE J. Sel. Top. Quantum Electron.

M. Fujita, Y. Tanaka, and S. Noda, “Light emission from silicon in photonic crystal nanocavity,” IEEE J. Sel. Top. Quantum Electron. 14, 1090–1097 (2008). [CrossRef]

IEEE Trans. Electron Devices

T. Tiedje, E. Yablonovitch, G. D. Cody, and B. G. Brooks, “Limiting efficiency of silicon solar cells,” IEEE Trans. Electron Devices ED-31, 711–716 (1984). [CrossRef]

J. Am. Chem. Soc.

J. Pang, S. Xiong, F. Jaeckel, Z. Sun, D. Dunphy, and C. J. Brinker, “Free-standing, patternable nanoparticle/polymer monolayer arrays formed by evaporation induced self-assembly at a fluid interface,” J. Am. Chem. Soc. 130, 3284–3285 (2008). [CrossRef] [PubMed]

J. Chem. Phys.

J. M. An, M. Califano, A. Franceschetti, and A. Zunger, “Excited-state relaxation in PbSe quantum dots,” J. Chem. Phys. 128, 164720 (2008). [CrossRef] [PubMed]
V. A. Mandelshtam and H. S. Taylor, “Harmonic inversion of time signals and its applications,” J. Chem. Phys. 107, 6756–6769(1997). [CrossRef]
A. D. Stein and M. D. Fayer, “Spectral diffusion in liquids,” J. Chem. Phys. 97, 2948–2962 (1992). [CrossRef]

J. Comput. Electron.

S. Liao, M. Dutta, D. Schonfeld, T. Yamanaka, and M. Stroscio, “Quantum dot blinking: relevance to physical limits for nanoscale optoelectronic device,” J. Comput. Electron. 7, 462–465(2008). [CrossRef]

J. Lightwave Technol.

M. Boroditsky, R. Vrijen, T. F. Krauss, R. Coccioli, R. Bhat, and E. Yablonovitch, “Spontaneous emission extraction and Purcell enhancement from thin-film 2-D photonic crystals,” J. Lightwave Technol. 17, 2096–2112 (1999). [CrossRef]

J. Opt. Soc. Am. B

J. Phys. Chem. C

S. W. Clark, J. M. Harbold, and F. W. Wise, “Resonant energy transfer in PbS quantum dots,” J. Phys. Chem. C 111, 7302–7305 (2007). [CrossRef]

Luminescence

E. He, H. Zheng, X. Zhang, and S. Qu, “Local-field effect on the fluorescence relaxation of Tm3+:LaF3 nanocrystals immersed in liquid medium,” Luminescence 25, 66–70 (2010). [CrossRef]

Nano Lett.

J. J. Peterson and T. D. Krauss, “Fluorescence spectroscopy of single lead sulfide quantum dots,” Nano Lett. 6, 510–514 (2006). [CrossRef] [PubMed]
M. Ji, S. Park, S. T. Connor, T. Mokari, Y. Cui, and K. J. Gaffney, “Efficient multiple exciton generation observed in colloidal PbSe quantum dots with temporally and spectrally resolved intraband excitation,” Nano Lett. 9, 1217–1222 (2009). [CrossRef] [PubMed]
A. G. Pattantyus-Abraham, H. Qiao, J. Shan, K. A. Abel, T.-S. Wang, F. C. J. M. van Veggel, and J. F. Young, “Site-selective optical coupling of PbSe nanocrystals to Si-based photonic crystal microcavities,” Nano Lett. 9, 2849–2854 (2009). [CrossRef] [PubMed]

Nat. Nanotechnol.

N. Ganesh, W. Zhang, P. C. Mathias, E. Chow, J. A. N. T. Soares, V. Malyarchuk, A. D. Smith, and B. T. Cunningham, “Enhanced fluorescence emission from quantum dots on a photonic crystal surface,” Nat. Nanotechnol. 2, 515–520 (2007). [CrossRef]

Nat. Photon.

S. Ates, S. M. Ulrich, A. Ulhaq, S. Reitzenstein, A. Loffler, S. Hofling, A. Forchel, and P. Michler, “Non-resonant dot-cavity coupling and its potential for resonant single-quantum-dot spectroscopy,” Nat. Photon. 3, 724–728 (2009). [CrossRef]
G. Sallen, A. Tribu, T. Aichele, R. Andre, L. Besombes, C. Bougerol, M. Richard, S. Tatarenko, K. Kheng, and J. P. Poizat, “Subnanosecond spectral diffusion measurement using photon correlation,” Nat. Photon. 4, 696–699 (2010). [CrossRef]
A. J. Shields, “Semiconductor quantum light sources,” Nat. Photon. 1, 215–223 (2007). [CrossRef]

Nat. Phys.

G. Khitrova, H. M. Gibbs, M. Kira, S. W. Koch, and A. Scherer, “Vacuum Rabi splitting in semiconductors,” Nat. Phys. 2, 81–90 (2006). [CrossRef]

Nature

P. Michler, A. Imamoglu, M. D. Mason, P. J. Carson, G. F. Strouse, and S. K. Buratto, “Quantum correlation among photons from a single quantum dot at room temperature,” Nature 406, 968–970 (2000). [CrossRef] [PubMed]
K. J. Vahala, “Optical microcavities,” Nature 424, 839–846(2003). [CrossRef] [PubMed]
J. Wiersig, C. Gies, F. Jahnke, M. Aszmann, T. Berstermann, M. Bayer, C. Kistner, S. Reitzenstein, C. Schneider, S. Hofling, A. Forchel, C. Kruse, J. Kalden, and D. Hommel, “Direct observation of correlations between individual photon emission events of a microcavity laser,” Nature 460, 245–249 (2009). [CrossRef] [PubMed]
C. Santori, D. Fattal, J. Vuckovic, G. S. Solomon, and Y. Yamamoto, “Indistinguishable photons from a single-photon device,” Nature 419, 594–597 (2002). [CrossRef] [PubMed]
Y. Akahane, T. Asano, B. S. Song, and S. Noda, “High-Q photonic nanocavity in a two-dimensional photonic crystal,” Nature 425 (2003). [CrossRef] [PubMed]

Nature Phys.

A. Faraon, I. Fushman, D. Englund, N. Stoltz, P. Petroff, and J. Vuckovic, “Coherent generation of non-classical light on a chip via photon-induced tunnelling and blockade,” Nature Phys. 4, 859–863 (2008). [CrossRef]

Opt. Express

Opt. Lett.

Phys. Lett. A

M. E. Crenshaw, “The quantized field in a dielectric and application to the radiative decay of an embedded atom,” Phys. Lett. A 358, 438–442 (2006). [CrossRef]

Phys. Rev. A

R. J. Glauber and M. Lewenstein, “Quantum optics of dielectric media,” Phys. Rev. A 43, 467–491 (1991). [CrossRef] [PubMed]
G. S. Agarwal and S. D. Gupta, “Microcavity-induced modification of the dipole-dipole interaction,” Phys. Rev. A 57, 667–670 (1998). [CrossRef]
T. Kobayashi, Q. Zheng, and T. Sekiguchi, “Resonant dipole-dipole interaction in a cavity,” Phys. Rev. A 52, 2835–2846(1995). [CrossRef] [PubMed]
Y. Xu, R. K. Lee, and A. Yariv, “Finite-difference time-domain analysis of spontaneous emission in a microdisk cavity,” Phys. Rev. A 61, 033808 (2000). [CrossRef]

Phys. Rev. B

N.-V.-Q. Tran, S. Combrie, and A. De Rossi, “Directive emission from high-Q photonic crystal cavities through band folding,” Phys. Rev. B 79, 041101 (2009). [CrossRef]
A. Kress, F. Hofbauer, N. Reinelt, M. Kaniber, H. J. Krenner, R. Meyer, G. Bohm, and J. J. Finley, “Manipulation of the spontaneous emission dynamics of quantum dots in two-dimensional photonic crystals,” Phys. Rev. B 71, 241304(R) (2005). [CrossRef]
J.-K. Hwang, H.-Y. Ryu, and Y.-H. Lee, “Spontaneous emission rate of an electric dipole in a general microcavity,” Phys. Rev. B 60, 4688–4695 (1999). [CrossRef]
J. M. Harbold and F. W. Wise, “Photoluminescence spectroscopy of PbSe nanocrystals,” Phys. Rev. B 76, 125304 (2007). [CrossRef]

Phys. Rev. Lett.

S. Fan, P. R. Villeneuve, J. D. Joannopoulos, and E. F. Schubert, “High extraction efficiency of spontaneous emission from slabs of photonic crystals,” Phys. Rev. Lett. 78, 3294–3297 (1997). [CrossRef]
R. D. Schaller, J. M. Pietryga, S. V. Goupalov, M. A. Petruska, S. A. Ivanov, and V. I. Klimov, “Breaking the phonon bottleneck in semiconductor nanocrystals via multiphonon emission induced by intrinsic nonadiabatic interactions,” Phys. Rev. Lett. 95, 196401 (2005). [CrossRef] [PubMed]
M. E. Crenshaw and C. M. Bowden, “Effects of local fields on spontaneous emission in dielectric media,” Phys. Rev. Lett. 85, 1851–1854 (2000). [CrossRef] [PubMed]
P. R. Berman and P. W. Milonni, “Microscopic theory of modified spontaneous emission in a dielectric,” Phys. Rev. Lett. 92, 053601 (2004). [CrossRef] [PubMed]
T. Lund-Hansen, S. Stobbe, B. Julsgaard, H. Thyrrestrup, T. Sunner, M. Kamp, A. Forchel, and P. Lodahl, “Experimental realization of highly efficient broadband coupling of single quantum dots to a photonic crystal waveguide,” Phys. Rev. Lett. 101, 113903 (2008). [CrossRef] [PubMed]
M. Pelton, C. Santori, J. Vuckovic, B. Zhang, G. S. Solomon, J. Plant, and Y. Yamamoto, “Efficient source of single photons: a single quantum dot in a micropost microcavity,” Phys. Rev. Lett. 89, 233602 (2002). [CrossRef] [PubMed]

Rep. Prog. Phys.

B. Lounis and M. Orrit, “Single-photon sources,” Rep. Prog. Phys. 68, 1129–1179 (2005). [CrossRef]

Science

I. Fushman, D. Englund, A. Faraon, N. Stoltz, P. Petroff, and J. Vuckovic, “Controlled phase shifts with a single quantum dot,” Science 320, 769–772 (2008). [CrossRef] [PubMed]
H. Fan, K. Yang, D. M. Boye, T. Sigmon, K. J. Malloy, H. Xu, G. P. López, and C. J. Brinker, “Self-assembly of ordered, robust, three-dimensional gold nanocrystal/silica arrays,” Science 304, 567–571 (2004). [CrossRef] [PubMed]
V. I. Klimov, A. A. Mikhailovsky, S. Xu, A. Malko, J. A. Hollingsworth, C. A. Leatherdale, H. J. Eisler, and M. G. Bawendi, “Optical gain and stimulated emission in nanocrystal quantum dots,” Science 290, 314–317 (2000). [CrossRef] [PubMed]
P. Andrew and W. L. Barnes, “Förster energy transfer in an optical microcavity,” Science 290, 785–788 (2000). [CrossRef] [PubMed]

Small

S. Xiong, X. Miao, J. Spencer, C. Khripin, T. S. Luk, and C. J. Brinker, “Integration of a close-packed quantum dot monolayer with a photonic-crystal cavity via interfacial self-assembly and transfer,” Small 6, 2126–2129 (2010). [CrossRef] [PubMed]

Other

J. D. Joannopoulos, S. G. Johnson, J. N. Winn, and R. D. Meade, Photonic Crystals Molding the Flow of Light (Princeton Univ. Press, 2008).
J. M. Phillips, P. E. Burrows, R. F. Daves, J. A. Simmons, G. G. Malliaras, F. So, J. A. Misewich, A. V. Nurmikko, and D. L. Smith, “Basic research needs for solid-state lighting,” Basic Energy Sciences report (U.S. Department of Energy, 2006), http://www.sc.doe.gov/bes/reports/files/SSL_rpt.pdf.
A. Majundar, Y. Y. Gong, E. D. Kim, and J. Vuckovic, “Phonon mediated off-resonant quantum dot-cavity coupling,” arXiv:1012.3125v1 (2010).
H. A. Lorentz, Theory of Electrons and Its Applications to the Phenomena of Light and Radiant Heat (Stechert, 1916).

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

Click here to see a list of articles that cite this paper