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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 19, Iss. 19 — Sep. 12, 2011
  • pp: 18237–18245
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Plasmonic crystal defect nanolaser

Amit M. Lakhani, Myung-ki Kim, Erwin K. Lau, and Ming C. Wu  »View Author Affiliations


Optics Express, Vol. 19, Issue 19, pp. 18237-18245 (2011)
http://dx.doi.org/10.1364/OE.19.018237


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Abstract

Surface plasmons are widely interesting due to their ability to probe nanoscale dimensions. To create coherent plasmons, we demonstrate a nanolaser based on a plasmonic bandgap defect state inside a surface plasmonic crystal. A one-dimensional semiconductor-based plasmonic crystal is engineered to have stopbands in which surface plasmons are prohibited from travelling in the crystalline structure. We then confine surface plasmons using a three-hole defect in the periodic structure. Using conventional III-V semiconductors, we achieve lasing in mode volumes as small as Veff = 0.3(λ0 /n)3 at λ0 = 1342 nm, which is 10 times smaller than similar modes in photonic crystals of the same size. This demonstration should pave the way for achieving engineered nanolasers with deep-subwavelength mode volumes and attractive nanophotonics integration capabilities while enabling the use of plasmonic crystals as an attractive platform for designing plasmons.

© 2011 OSA

1. Introduction

Nanophotonic circuits/devices using metal-optics/surface plasmons uniquely manipulate light below the diffraction limit, enabling countless applications including imaging [1

1. N. Fang, H. Lee, C. Sun, and X. Zhang, “Sub-diffraction-limited optical imaging with a silver superlens,” Science 308(5721), 534–537 (2005). [CrossRef] [PubMed]

], data storage [2

2. W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. M. Yang, X. Zhu, N. J. Gokemeijer, Y. T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics 3(4), 220–224 (2009). [CrossRef]

], optical sensing [3

3. P. Alivisatos, “The use of nanocrystals in biological detection,” Nat. Biotechnol. 22(1), 47–52 (2004). [CrossRef] [PubMed]

5

5. A. Artar, A. A. Yanik, and H. Altug, “Fabry–Pérot nanocavities in multilayered plasmonic crystals for enhanced biosensing,” Appl. Phys. Lett. 95(5), 051105 (2009). [CrossRef]

], and optical interconnection [6

6. D. Miller, “Device requirements for optical interconnects to silicon chips,” Proc. IEEE 97(7), 1166–1185 (2009). [CrossRef]

,7

7. J. A. Dionne, L. A. Sweatlock, M. T. Sheldon, A. P. Alivisatos, and H. A. Atwater, “Silicon-based plasmonics for on-chip photonics,” IEEE J. Sel. Top. Quantum Electron. 16(1), 295–306 (2010). [CrossRef]

]. Passive plasmonic structures such as waveguides [7

7. J. A. Dionne, L. A. Sweatlock, M. T. Sheldon, A. P. Alivisatos, and H. A. Atwater, “Silicon-based plasmonics for on-chip photonics,” IEEE J. Sel. Top. Quantum Electron. 16(1), 295–306 (2010). [CrossRef]

,8

8. R. F. Oulton, V. J. Sorger, D. A. Genov, D. F. P. Pile, and X. Zhang, “A hybrid plasmonic waveguide for subwavelength confinement and long-range propagation,” Nat. Photonics 2(8), 496–500 (2008). [CrossRef]

], resonators [9

9. H. T. Miyazaki and Y. Kurokawa, “Controlled plasmon resonance in closed metal/insulator/metal nanocavities,” Appl. Phys. Lett. 89(21), 211126 (2006). [CrossRef]

,10

10. V. J. Sorger, R. F. Oulton, J. Yao, G. Bartal, and X. Zhang, “Plasmonic Fabry-Pérot nanocavity,” Nano Lett. 9(10), 3489–3493 (2009). [CrossRef] [PubMed]

], and interferometers [11

11. S. I. Bozhevolnyi, V. S. Volkov, E. Devaux, J.-Y. Laluet, and T. W. Ebbesen, “Channel plasmon subwavelength waveguide components including interferometers and ring resonators,” Nature 440(7083), 508–511 (2006). [CrossRef] [PubMed]

] have been demonstrated. Nanolasers with the ability to easily couple into nanophotonic circuits have become critical to realize nanoscale optics since external lasers suffer from low coupling efficiency [2

2. W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. M. Yang, X. Zhu, N. J. Gokemeijer, Y. T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics 3(4), 220–224 (2009). [CrossRef]

] even with designed couplers [12

12. D. F. P. Pile and D. K. Gramotnev, “Adiabatic and nonadiabatic nanofocusing of plasmons by tapered gap plasmon waveguides,” Appl. Phys. Lett. 89(4), 041111 (2006). [CrossRef]

,13

13. S. Vedantam, H. Lee, J. Tang, J. Conway, M. Staffaroni, and E. Yablonovitch, “A plasmonic dimple lens for nanoscale focusing of light,” Nano Lett. 9(10), 3447–3452 (2009). [CrossRef] [PubMed]

]. Recently, several nanolasers have been reported using varying degrees of dielectric and metallic confinement to achieve subwavelength mode volumes [14

14. M. T. Hill, Y.-S. Oei, B. Smalbrugge, Y. Zhu, T. de Vries, P. J. van Veldhoven, F. W. M. van Otten, T. J. Eijkemans, J. P. Turkiewicz, H. de Waardt, E. J. Geluk, S.-H. Kwon, Y.-H. Lee, R. Notzel, and M. K. Smit, “Lasing in metallic-coated nanocavities,” Nat. Photonics 1(10), 589–594 (2007). [CrossRef]

24

24. K. Ding, Z. Liu, L. Yin, H. Wang, R. Liu, M. T. Hill, M. J. H. Marell, P. J. van Veldhoven, R. Nötzel, and C. Z. Ning, “Electrical injection, continuous wave operation of subwavelength-metallic-cavity lasers at 260 K,” Appl. Phys. Lett. 98(23), 231108 (2011). [CrossRef]

], shrinking lasers beyond traditional dielectric cavities [25

25. S. L. McCall, A. F. J. Levi, R. E. Slusher, S. J. Pearton, and R. A. Logan, “Whispering-gallery mode microdisk lasers,” Appl. Phys. Lett. 60(3), 289 (1992). [CrossRef]

28

28. S. Reitzenstein, T. Heindel, C. Kistner, A. Rahimi-Iman, C. Schneider, S. Hofling, and A. Forchel, “Low threshold electrically pumped quantum dot-micropillar lasers,” Appl. Phys. Lett. 93(6), 061104 (2008). [CrossRef]

]. Among these, surface-plasmon-based nanolasers [16

16. M. A. Noginov, G. Zhu, A. M. Belgrave, R. Bakker, V. M. Shalaev, E. E. Narimanov, S. Stout, E. Herz, T. Suteewong, and U. Wiesner, “Demonstration of a spaser-based nanolaser,” Nature 460(7259), 1110–1112 (2009). [CrossRef] [PubMed]

,17

17. R. F. Oulton, V. J. Sorger, T. Zentgraf, R.-M. Ma, C. Gladden, L. Dai, G. Bartal, and X. Zhang, “Plasmon lasers at deep subwavelength scale,” Nature 461(7264), 629–632 (2009). [CrossRef] [PubMed]

,21

21. S.-H. Kwon, J.-H. Kang, C. Seassal, S.-K. Kim, P. Regreny, Y.-H. Lee, C. M. Lieber, and H.-G. Park, “Subwavelength plasmonic lasing from a semiconductor nanodisk with silver nanopan cavity,” Nano Lett. 10(9), 3679–3683 (2010). [CrossRef] [PubMed]

,23

23. R.-M. Ma, R. F. Oulton, V. J. Sorger, G. Bartal, and X. Zhang, “Room-temperature sub-diffraction-limited plasmon laser by total internal reflection,” Nat. Mater. 10(2), 110–113 (2011). [CrossRef] [PubMed]

] have been demonstrated as enablers to plasmonic circuits. Yet, easy design of nanophotonic circuits will only be possible with a unifying platform where active and passive components can exist simultaneously.

Recently, Kim et al. have theorized that combining concepts from photonic crystal structures with plasmonics can be a powerful way to engineer coupled subwavelength light sources with passive components [29

29. M.-K. Kim, S. H. Lee, M. Choi, B.-H. Ahn, N. Park, Y.-H. Lee, and B. Min, “Low-loss surface-plasmonic nanobeam cavities,” Opt. Express 18(11), 11089–11096 (2010). [CrossRef] [PubMed]

]. In conventional photonic crystal lasers [30

30. O. Painter, R. K. Lee, A. Scherer, A. Yariv, J. D. O’Brien, P. D. Dapkus, and I. Kim, “Two-dimensional photonic band-Gap defect mode laser,” Science 284(5421), 1819–1821 (1999). [CrossRef] [PubMed]

,31

31. H.-G. Park, S.-H. Kim, S.-H. Kwon, Y.-G. Ju, J.-K. Yang, J.-H. Baek, S.-B. Kim, and Y.-H. Lee, “Electrically driven single-cell photonic crystal laser,” Science 305(5689), 1444–1447 (2004). [CrossRef] [PubMed]

], the mode patterns and coupling schemes of lasers are easily engineered by designing the size and location of the air holes [32

32. H. Matsubara, S. Yoshimoto, H. Saito, Y. Jianglin, Y. Tanaka, and S. Noda, “GaN photonic-crystal surface-emitting laser at blue-violet wavelengths,” Science 319(5862), 445–447 (2008). [CrossRef] [PubMed]

,33

33. Y. Kurosaka, S. Iwahashi, Y. Liang, K. Sakai, E. Miyai, W. Kunishi, D. Ohnishi, and S. Noda, “On-chip beam-steering photonic-crystal lasers,” Nat. Photonics 4(7), 447–450 (2010). [CrossRef]

]. However, the laser mode is limited by the diffraction limit [30

30. O. Painter, R. K. Lee, A. Scherer, A. Yariv, J. D. O’Brien, P. D. Dapkus, and I. Kim, “Two-dimensional photonic band-Gap defect mode laser,” Science 284(5421), 1819–1821 (1999). [CrossRef] [PubMed]

,34

34. Y. Gong, B. Ellis, G. Shambat, T. Sarmiento, J. S. Harris, and J. Vuckovic, “Nanobeam photonic crystal cavity quantum dot laser,” Opt. Express 18(9), 8781–8789 (2010). [CrossRef] [PubMed]

]. To overcome this hurdle, we demonstrate a nanolaser based on a defect inside a surface plasmon polariton crystal (SPPC or plasmonic crystal). A SPPC is simply a periodic structure on a metal film capable of manipulating surface plasmons at the metal/dielectric interface. It is engineered to have stopbands that inhibit travelling surface plasmons of certain frequencies. Recent attempts at creating such devices have not been able to overcome resistive losses [35

35. T. Okamoto, F. H’Dhili, and S. Kawata, “Towards plasmonic band gap laser,” Appl. Phys. Lett. 85(18), 3968 (2004). [CrossRef]

]. In this paper, we experimentally localize plasmon oscillations using a defect in this periodic structure and achieve lasing in mode volumes of Veff = 0.3 (λ0/n)3 at λ0 = 1342 nm for the first time. We envision that plasmonic crystals will be useful for not only nanolasers, but also Purcell-enhanced light-emitting diodes capable of modulation speeds >100GHz due to the exquisite controllability of electromagnetic mode volumes [36

36. E. K. Lau, A. Lakhani, R. S. Tucker, and M. C. Wu, “Enhanced modulation bandwidth of nanocavity light emitting devices,” Opt. Express 17(10), 7790–7799 (2009). [CrossRef] [PubMed]

]. With this nanolaser demonstration, we enable plasmonic crystals to become a new paradigm for the development of robust and engineered active nanophotonic circuits capable of incorporating deep-subwavelength light emitters.

2. Device geometry and fabrication

In Fig. 1a
Fig. 1 (a) A schematic of a one-dimensional plasmonic crystal. The nanobeam consists of a direct-gap semiconductor material (InGaAsP) with a 5 nm TiO2 dielectric barrier and a 10 nm InP barrier between it and the metal. The 3 nm Ti adhesion layer is left off for simplicity. The device has three air holes missing in the middle of the device, creating a defect in the periodic structure. The beam is 225 nm thick and w wide with air holes of diameter d spaced apart by lattice constant a. (b) A scanning electron micrograph of a one-dimensional plasmonic crystal. The scale bar represents 1 μm.
, we show the geometry of the plasmonic crystal defect nanolaser. A periodically patterned nanobeam of InGaAsP/InP is placed on a 100-nm thick gold film with a 3nm Ti adhesion layer and a 5 nm TiO2 spacer layer. The device has three air holes missing in the center and has a width w, lattice constant a, and hole diameter d. The nanobeam consists of a 200-nm InGaAsP layer sandwiched by 10 nm of InP barrier material. The metal underneath the semiconductor is as smooth as the initial semiconductor surface due to the nature of the fabrication process. However, after RIE etching, the metal surface surrounding the device is roughened, although the exact average roughness was not measured. A fabricated device can be seen in Fig. 1b. Details of the fabrication process are described elsewhere [18

18. K. Yu, A. Lakhani, and M. C. Wu, “Subwavelength metal-optic semiconductor nanopatch lasers,” Opt. Express 18(9), 8790–8799 (2010). [CrossRef] [PubMed]

].

3. Properties of plasmonic crystals

A plasmonic crystal is heavily influenced by the presence of the metal film compared to a photonic crystal structure surrounded completely by air of the same size. In Fig. 2
Fig. 2 We contrast the plasmonic crystal with a photonic crystal of the same dimensions. (a) The simulated band structure for the plasmonic crystal device in Fig. 3a. We show the first six bands of the device (A-F). The bands are labeled red (TM/plasmonic) and blue (TE/photonic). We also highlight the presence of two plasmonic bandgaps that appear only in the plasmonic crystal (versus a photonic crystal). A three hole defect in the device introduces multiple defect eigenmodes shown as black stars at the Broullion zone edge. (b) We show the simulated band structure for a photonic crystal with exact dimensions in Fig. 3a but without the metal substrate. The bands are labeled to correspond to a particular travelling wave of a plasmonic crystal (e.g. A’ in a photonic crystal corresponds with A in the plasmonic crystal). The photonic crystal has only a TE bandgap that extends from 222 THz to beyond 300 THz with a defect mode, α’ due to a three hole defect.
, we contrast various aspects of plasmonic and photonic crystals. In Fig. 2a and 2b, we show the simulated dispersion of the device shown in Fig. 6a
Fig. 6 We observe lasing in the γ defect mode of a SPPC and show the electromagnetic properties of a γ-defect nanolaser. (a) SEM micrograph of a device in which the γ defect mode lases. It has a lattice constant of a = 343 nm. (b,c) The top (x-z) view and the side (y-z) view of the electric energy density of the γ defect resonance (d,e) The simulated z-polarized and x-polarized far-field radiation directivity of the γ defect mode. The device is shown for reference. (f,g) Experimentally obtained z-polarized and x-polarized images of the γ lasing mode.
below with and without a metal film, respectively. The crystal dispersion was generated using finite difference time domain (FDTD) techniques with periodic boundary conditions. In a photonic crystal, the TM modes operate at much higher frequency relative to the SPPC and do not form a bandgap (e.g. A’ and B’ are nearly degenerate at the Brillouin zone edge). The dielectric structure does, however, have a bandgap for TE travelling waves. In contrast, in a plasmonic crystal, the TM travelling waves present in the photonic crystal interact heavily with the metal film and become surface plasmons (Fig. 3
Fig. 3 We contrast the different bands for a plasmonic and photonic crystal of the same dimensions. The bands are labeled to correspond to Fig. 1. (a, b, c, d, e, f) The electric field magnitude plots of the first four plasmonic bands (A-D) and the first two photonic bands (E,I) are presented for a SPPC. The charge distribution of the plasmon-like (TM) bands (A-D) are overlaid on the field distribution plots. Each pair of plots correspond to a color map of |E| along the cross-section defined by the dashed white line on the corresponding figure. The left plot is in the x-z plane, while the right figure is in the y-z plane. Bands A, B, C, D, E, and I resonate at 190, 204, 214, 229, 243, and 327 THz, respectively. (g, h, i, j, k, l) In a similar manner, we show the electric field magnitude plots of the first six bands for a photonic crystal in order of increasing resonance frequency (E’, B’, A’, C’, I’, and D’ resonate at 222, 282, 283, 295, 310, and 312 THz, respectively).
). As a result, their operating frequencies drop (e.g. band A’ is at 280 THz while band A is at 190 THz at the band-edge), and, more importantly, the metal film interaction separates the photonic TM modes at the crystal band-edge and allows for the creation of defects that can successfully confine plasmons in a SPPC. These pseudo-bandgaps appear at the edge of the Brillouin zone between bands A and B and also between bands C and D (Fig. 2a). Finally, the metal film breaks the symmetry of the photonic crystal in the y-direction, causing the non-interacting photonic modes to blue shift.

Using the absence of three holes in the middle of the crystal, multiple defect modes can be created. Because of the large difference between the two devices, the fundamental defect modes (α and α’) for both structures in Fig. 4
Fig. 4 (a) A profile in the y-z plane of the electric energy density of the α defect mode in a plasmonic crystal with metal beneath the semiconductor beam. The defect mode is TM/plasmonic in nature. (b) Another profile in the y-z plane of the electric energy density of the α’ defect mode of the photonic crystal. This mode is TE/photonic in nature in contrast to the α defect mode
also have different characteristics. The α’ mode resonates at 235THz and is TE, while α resonates at 193 THz and is TM; the photonic crystal would have to be roughly ~1.25 times larger to match the plasmonic crystal resonance frequency (more size reduction is expected in visible frequencies due to the nature of surface plasmon wavevectors). We define the electromagnetic mode volume of the lasing mode as Veff = ∫(∂(ωε(r,ω))/∂ω)|E(r)| 2 d 3 r/ max((∂(ωε(r,ω))/∂ω)|E(r)| 2) so that the photonic crystal defect has Veff,α' = 0.6 (λ0/n)3 while the plasmonic defect mode has a volume of Veff,α = 0.1 (λ0/n)3. The maximum energy point was found to be in the semiconductor for the α mode. Thus, the plasmonic α defect mode volume is 6 times smaller than the photonic counterpart.

4. Plasmonic crystal defect modes

In the SPPC, we observe lasing with the γ and δ defect modes. The α and β defect modes are not experimentally observed in this study probably due to insufficient gain with the current material system and the use of titanium as an adhesion layer between the gold and semiconductor interface [37

37. C. Jeppesen, N. A. Mortensen, and A. Kristensen, “The effect of Ti and ITO adhesion layers on gold split-ring resonators,” Appl. Phys. Lett. 97(26), 263103 (2010). [CrossRef]

]. In the future, low-loss metals and high-gain semiconductors will elucidate these modes. We show a summary of different relevant laser parameters for the first four defect modes of a 3-hole cavity in a plasmonic crystal in Fig. 5a
Fig. 5 (a) Summary table of relevant laser parameters of the first four eigenmodes of a 3-hole defect in a one-dimensional plasmonic crystal. (b,c) The top and side profiles of the electric energy density of the α and β defect modes. Both modes are surface plasmon modes that decay evanescently from the gold/semiconductor interface.
. We also show the mode profiles for the α and β defect modes in Figs. 5b and 5c, respectively.

5. Experimental results

The plasmonic crystal defect lasers were studied using pulsed optical pumping at 77 Kelvin. Details of the measurement setup are found elsewhere [18

18. K. Yu, A. Lakhani, and M. C. Wu, “Subwavelength metal-optic semiconductor nanopatch lasers,” Opt. Express 18(9), 8790–8799 (2010). [CrossRef] [PubMed]

]. Out of the many working devices that were fabricated, we have chosen one to illustrate lasing from the γ defect mode (Fig. 6a). Taking geometrical measurements from SEM, the device was simulated using Finite Integral technique (FIT) and the computed eigenfrequencies of various resonances agreed well with experimental data (Fig. 7). Using micro-photoluminescence, we verify that the band edge modes appear brightest when the edge of the device is optically pumped, whereas the defect mode only lases when the center of the device is pumped. In almost all instances, lasing is seen from band edge modes as well (Fig. 8
Fig. 8 We show laser characteristics from band D. (a) We show a lasing spectrum obtained at a peak pump power of 380 kW/cm2. (b) The semi-log scale pump-dependent spectra for the band-mode. (c) The L-L curve shows that the bandedge mode has a sharper threshold than the γ defect mode. The threshold pump power for this device is 55kW/cm2 of peak power.
). To further verify that the γ mode was lasing, we imaged the radiation from the device ~5 μm above the sample plane under maximum pumping conditions using a 100X 0.8NA objective (Figs. 6f and 6g). These polarization-resolved patterns were compared to simulated far-field radiation directivity of the γ defect mode (Figs. 6d and 6e). There is strong qualitative correspondence between the measured and simulated patterns. Also, in simulation and experiment, the z-polarized light was 10 and 8 times weaker than the x-polarized light, respectively.

The lasing spectrum at maximum pumping power of the plasmonic crystal defect laser can be seen in Fig. 7c. The threshold pumping power was found to be ~100 kW/cm2. However, this threshold is artificially high, since not all the pump power was absorbed by the structure due to its size. The linewidth of the laser was found to be to 0.5 nm at maximum pumping power. The peak wavelength of the device also stabilizes as lasing is reached, since carrier dependent refractive index changes are stabilized due to carrier clamping. We also analyzed the pump-power-dependent light output (L-L curve) for the γ defect mode. The integrated intensity from the defect cavity mode is seen in Fig. 7d. The spontaneous emission rate is enhanced in the nanocavity due to high coupling of spontaneous emission into the laser mode (β) and the Purcell effect (F = (16/π2)(Q/Veff)(λ/n)3). The light output characteristics of the nanolaser (L-L curve) were analyzed using rate equations and previously published material parameters [18

18. K. Yu, A. Lakhani, and M. C. Wu, “Subwavelength metal-optic semiconductor nanopatch lasers,” Opt. Express 18(9), 8790–8799 (2010). [CrossRef] [PubMed]

]. Taking into account the above effects regarding spontaneous emission, a good fit of the experimental data was obtained using a rate equation model with a fitting parameter = 0.122 (Fig. 7d).

In order to calculate a realistic Purcell enhancement, an experimentally determined quality factor for each mode needs to be measured. However, because of loss and gain within the semiconductor material, an accurate measurement of quality factors is difficult. The quality factor of plasmonic crystal lasers is metal-loss dominated, and thus should improve at low temperatures. The lowest measured quality factor for the γ mode was Qmeas = 250. Yet, this quality factor probably does not represent the actual nature of the defect cavity. Thus, in fitting the product for each L-L curve, we used a range of values for quality factors of the cavity, keeping in mind that previously published results suggest that metal loss is decreased by 5 times at 77K relative to room temperature [14

14. M. T. Hill, Y.-S. Oei, B. Smalbrugge, Y. Zhu, T. de Vries, P. J. van Veldhoven, F. W. M. van Otten, T. J. Eijkemans, J. P. Turkiewicz, H. de Waardt, E. J. Geluk, S.-H. Kwon, Y.-H. Lee, R. Notzel, and M. K. Smit, “Lasing in metallic-coated nanocavities,” Nat. Photonics 1(10), 589–594 (2007). [CrossRef]

]. There is also uncertainty in the mode volume used in the Purcell factor calculation, since not every carrier recombines that the point of maximum energy density. We suggest that quality factors near 5 times the simulated quality factors (including Ti loss) are most accurate (Qmodel = 180), and the simulated mode volumes is also accurate (Veff = 0.30 (λ0/n)3) giving F = 15.33. Yet, even if we vary F = 1.5 – F = 21, the product changes only modestly from = 0.090-0.126, suggesting that a relatively good model for spontaneous emission can be ascertained even with uncertainty in cavity quality factors and mode volumes.

We also observed lasing from the plasmonic travelling waves inside the SPPC. At the edge of the Broullion zone of the plasmonic crystal, the group velocities of the travelling modes go to zero. Thus, very large gain can be achieved for bandedge modes in plasmonic crystal cavities. In Fig. 8, the lasing characteristics of band D are shown in a different device than in Fig. 6a but with very similar dimensions. The band edge mode can selectively lase when the device is pumped at the edge (away from the defect area). Band C is suppressed because it is not in the gain bandwidth in this particular device. In band D, the group velocity approaches zero at the band edge and at k~0.42 (2π/a) (Fig. 2a). Lasing in a plasmonic band mode seems to behave very classically with a sharp threshold, as seen in the pump vs. intensity characteristics of the representative device in Fig. 8c. Although we cannot know the mode volume and theoretical quality factor of the band mode laser, we estimate the product = 0.016 from simple fitting by rate equation analysis. Thus, the spontaneous emission coupling is greatly reduced relative to a localized defect mode seen in Fig. 7.

6. Discussion and Conclusion

This particular demonstration of a SPPC-based nanolaser highlights only the beginning of this technology’s potential. In the future, plasmonic crystals, like their photonic counterparts, should be able to confine plasmons to one-half of a wavelength (λsp/2) .Thus, single-sided SPPCs should be able to squeeze electromagnetic mode volumes to less than 0.01 (λ 0/n)3 at visible frequencies, where n = 3.5 and the surface plasmon is propagating at a gold/semiconductor interface. In the near-infrared frequency range, using single-hole defects will further reduce the mode volume of our cavities. Utilizing better fabrication techniques without a lossy titanium layer should further allow our nanolaser to operate in the α mode, which is 3 times smaller in electromagnetic mode volume. Metal-semiconductor-metal geometries coupled with plasmonic crystals will also be able to squeeze mode volumes much below the limit of a single-sided surface plasmon at near-infrared frequencies [9

9. H. T. Miyazaki and Y. Kurokawa, “Controlled plasmon resonance in closed metal/insulator/metal nanocavities,” Appl. Phys. Lett. 89(21), 211126 (2006). [CrossRef]

,15

15. M. T. Hill, M. Marell, E. S. P. Leong, B. Smalbrugge, Y. Zhu, M. Sun, P. J. van Veldhoven, E. J. Geluk, F. Karouta, Y.-S. Oei, R. Nötzel, C.-Z. Ning, and M. K. Smit, “Lasing in metal-insulator-metal sub-wavelength plasmonic waveguides,” Opt. Express 17(13), 11107–11112 (2009). [CrossRef] [PubMed]

]. Finally, SPPC’s (especially metal-semiconductor-metal geometries) promise facile implementation of electrically-driven nano-emitters coupled to plasmonic waveguides since the metal can also serve as contacts [28

28. S. Reitzenstein, T. Heindel, C. Kistner, A. Rahimi-Iman, C. Schneider, S. Hofling, and A. Forchel, “Low threshold electrically pumped quantum dot-micropillar lasers,” Appl. Phys. Lett. 93(6), 061104 (2008). [CrossRef]

].

In summary, we have successfully shown the operation of a plasmonic crystal defect laser within a plasmonic bandgap based upon semiconductor technology. This laser benefits from small mode volumes with Veff = 0.3(λ 0/ n)3 at λ0 = 1342 nm, making it 10 times smaller than a similar mode in a photonic crystal of the same physics dimensions. This initial demonstration of a nanolaser based on plasmonic crystals should enable to use of these structures to generate coherent plasmons and control them in great detail, making them suitable as a future nanophotonics platform. The integration of the nanolaser with a plasmonic crystal while maintaining ultra-small mode volumes makes a plasmonic crystal defect laser a strong contender as a coherent light source for nano-opto-electronics in the future and enables the use of plasmonic crystals as a tool for mode volume engineering for all nano-light-emitters.

Acknowledgments

The authors would like to thank Michael Eggleston, Ryan Going, and Tae Joon Seok for their helpful discussion. This material is based upon work supported under a National Science Foundation Graduate Research Fellowship. This project was also supported by DARPA NACHOS (W911NF-07-1-0314), the NSF Center for Integrated Access Networks (CIAN) (EEC-08120702), the NSF Center for Energy Efficient Electronics Science (E3S) (ECCS-0939514), and Samsung GRO (20101554).

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P. Alivisatos, “The use of nanocrystals in biological detection,” Nat. Biotechnol. 22(1), 47–52 (2004). [CrossRef] [PubMed]

4.

H. J. Lezec, J. A. Dionne, and H. A. Atwater, “Negative refraction at visible frequencies,” Science 316(5823), 430–432 (2007). [CrossRef] [PubMed]

5.

A. Artar, A. A. Yanik, and H. Altug, “Fabry–Pérot nanocavities in multilayered plasmonic crystals for enhanced biosensing,” Appl. Phys. Lett. 95(5), 051105 (2009). [CrossRef]

6.

D. Miller, “Device requirements for optical interconnects to silicon chips,” Proc. IEEE 97(7), 1166–1185 (2009). [CrossRef]

7.

J. A. Dionne, L. A. Sweatlock, M. T. Sheldon, A. P. Alivisatos, and H. A. Atwater, “Silicon-based plasmonics for on-chip photonics,” IEEE J. Sel. Top. Quantum Electron. 16(1), 295–306 (2010). [CrossRef]

8.

R. F. Oulton, V. J. Sorger, D. A. Genov, D. F. P. Pile, and X. Zhang, “A hybrid plasmonic waveguide for subwavelength confinement and long-range propagation,” Nat. Photonics 2(8), 496–500 (2008). [CrossRef]

9.

H. T. Miyazaki and Y. Kurokawa, “Controlled plasmon resonance in closed metal/insulator/metal nanocavities,” Appl. Phys. Lett. 89(21), 211126 (2006). [CrossRef]

10.

V. J. Sorger, R. F. Oulton, J. Yao, G. Bartal, and X. Zhang, “Plasmonic Fabry-Pérot nanocavity,” Nano Lett. 9(10), 3489–3493 (2009). [CrossRef] [PubMed]

11.

S. I. Bozhevolnyi, V. S. Volkov, E. Devaux, J.-Y. Laluet, and T. W. Ebbesen, “Channel plasmon subwavelength waveguide components including interferometers and ring resonators,” Nature 440(7083), 508–511 (2006). [CrossRef] [PubMed]

12.

D. F. P. Pile and D. K. Gramotnev, “Adiabatic and nonadiabatic nanofocusing of plasmons by tapered gap plasmon waveguides,” Appl. Phys. Lett. 89(4), 041111 (2006). [CrossRef]

13.

S. Vedantam, H. Lee, J. Tang, J. Conway, M. Staffaroni, and E. Yablonovitch, “A plasmonic dimple lens for nanoscale focusing of light,” Nano Lett. 9(10), 3447–3452 (2009). [CrossRef] [PubMed]

14.

M. T. Hill, Y.-S. Oei, B. Smalbrugge, Y. Zhu, T. de Vries, P. J. van Veldhoven, F. W. M. van Otten, T. J. Eijkemans, J. P. Turkiewicz, H. de Waardt, E. J. Geluk, S.-H. Kwon, Y.-H. Lee, R. Notzel, and M. K. Smit, “Lasing in metallic-coated nanocavities,” Nat. Photonics 1(10), 589–594 (2007). [CrossRef]

15.

M. T. Hill, M. Marell, E. S. P. Leong, B. Smalbrugge, Y. Zhu, M. Sun, P. J. van Veldhoven, E. J. Geluk, F. Karouta, Y.-S. Oei, R. Nötzel, C.-Z. Ning, and M. K. Smit, “Lasing in metal-insulator-metal sub-wavelength plasmonic waveguides,” Opt. Express 17(13), 11107–11112 (2009). [CrossRef] [PubMed]

16.

M. A. Noginov, G. Zhu, A. M. Belgrave, R. Bakker, V. M. Shalaev, E. E. Narimanov, S. Stout, E. Herz, T. Suteewong, and U. Wiesner, “Demonstration of a spaser-based nanolaser,” Nature 460(7259), 1110–1112 (2009). [CrossRef] [PubMed]

17.

R. F. Oulton, V. J. Sorger, T. Zentgraf, R.-M. Ma, C. Gladden, L. Dai, G. Bartal, and X. Zhang, “Plasmon lasers at deep subwavelength scale,” Nature 461(7264), 629–632 (2009). [CrossRef] [PubMed]

18.

K. Yu, A. Lakhani, and M. C. Wu, “Subwavelength metal-optic semiconductor nanopatch lasers,” Opt. Express 18(9), 8790–8799 (2010). [CrossRef] [PubMed]

19.

M. P. Nezhad, A. Simic, O. Bondarenko, B. Slutsky, A. Mizrahi, L. Feng, V. Lomakin, and Y. Fainman, “Room-temperature subwavelength metallo-dielectric lasers,” Nat. Photonics 4(6), 395–399 (2010). [CrossRef]

20.

C.-Y. Lu, S.-W. Chang, S. L. Chuang, T. D. Germann, and D. Bimberg, “Metal-cavity surface-emitting microlaser at room temperature,” Appl. Phys. Lett. 96(25), 251101 (2010). [CrossRef]

21.

S.-H. Kwon, J.-H. Kang, C. Seassal, S.-K. Kim, P. Regreny, Y.-H. Lee, C. M. Lieber, and H.-G. Park, “Subwavelength plasmonic lasing from a semiconductor nanodisk with silver nanopan cavity,” Nano Lett. 10(9), 3679–3683 (2010). [CrossRef] [PubMed]

22.

A. M. Lakhani, K. Yu, and M. C. Wu, “Lasing in subwavelength semiconductor nanopatches,” Semicond. Sci. Technol. 26(1), 014013 (2011). [CrossRef]

23.

R.-M. Ma, R. F. Oulton, V. J. Sorger, G. Bartal, and X. Zhang, “Room-temperature sub-diffraction-limited plasmon laser by total internal reflection,” Nat. Mater. 10(2), 110–113 (2011). [CrossRef] [PubMed]

24.

K. Ding, Z. Liu, L. Yin, H. Wang, R. Liu, M. T. Hill, M. J. H. Marell, P. J. van Veldhoven, R. Nötzel, and C. Z. Ning, “Electrical injection, continuous wave operation of subwavelength-metallic-cavity lasers at 260 K,” Appl. Phys. Lett. 98(23), 231108 (2011). [CrossRef]

25.

S. L. McCall, A. F. J. Levi, R. E. Slusher, S. J. Pearton, and R. A. Logan, “Whispering-gallery mode microdisk lasers,” Appl. Phys. Lett. 60(3), 289 (1992). [CrossRef]

26.

J. C. Johnson, H.-J. Choi, K. P. Knutsen, R. D. Schaller, P. Yang, and R. J. Saykally, “Single gallium nitride nanowire lasers,” Nat. Mater. 1(2), 106–110 (2002). [CrossRef] [PubMed]

27.

Z. Zhang, L. Yang, V. Liu, T. Hong, K. Vahala, and A. Scherer, “Visible submicron microdisk lasers,” Appl. Phys. Lett. 90(11), 111119 (2007). [CrossRef]

28.

S. Reitzenstein, T. Heindel, C. Kistner, A. Rahimi-Iman, C. Schneider, S. Hofling, and A. Forchel, “Low threshold electrically pumped quantum dot-micropillar lasers,” Appl. Phys. Lett. 93(6), 061104 (2008). [CrossRef]

29.

M.-K. Kim, S. H. Lee, M. Choi, B.-H. Ahn, N. Park, Y.-H. Lee, and B. Min, “Low-loss surface-plasmonic nanobeam cavities,” Opt. Express 18(11), 11089–11096 (2010). [CrossRef] [PubMed]

30.

O. Painter, R. K. Lee, A. Scherer, A. Yariv, J. D. O’Brien, P. D. Dapkus, and I. Kim, “Two-dimensional photonic band-Gap defect mode laser,” Science 284(5421), 1819–1821 (1999). [CrossRef] [PubMed]

31.

H.-G. Park, S.-H. Kim, S.-H. Kwon, Y.-G. Ju, J.-K. Yang, J.-H. Baek, S.-B. Kim, and Y.-H. Lee, “Electrically driven single-cell photonic crystal laser,” Science 305(5689), 1444–1447 (2004). [CrossRef] [PubMed]

32.

H. Matsubara, S. Yoshimoto, H. Saito, Y. Jianglin, Y. Tanaka, and S. Noda, “GaN photonic-crystal surface-emitting laser at blue-violet wavelengths,” Science 319(5862), 445–447 (2008). [CrossRef] [PubMed]

33.

Y. Kurosaka, S. Iwahashi, Y. Liang, K. Sakai, E. Miyai, W. Kunishi, D. Ohnishi, and S. Noda, “On-chip beam-steering photonic-crystal lasers,” Nat. Photonics 4(7), 447–450 (2010). [CrossRef]

34.

Y. Gong, B. Ellis, G. Shambat, T. Sarmiento, J. S. Harris, and J. Vuckovic, “Nanobeam photonic crystal cavity quantum dot laser,” Opt. Express 18(9), 8781–8789 (2010). [CrossRef] [PubMed]

35.

T. Okamoto, F. H’Dhili, and S. Kawata, “Towards plasmonic band gap laser,” Appl. Phys. Lett. 85(18), 3968 (2004). [CrossRef]

36.

E. K. Lau, A. Lakhani, R. S. Tucker, and M. C. Wu, “Enhanced modulation bandwidth of nanocavity light emitting devices,” Opt. Express 17(10), 7790–7799 (2009). [CrossRef] [PubMed]

37.

C. Jeppesen, N. A. Mortensen, and A. Kristensen, “The effect of Ti and ITO adhesion layers on gold split-ring resonators,” Appl. Phys. Lett. 97(26), 263103 (2010). [CrossRef]

OCIS Codes
(140.5960) Lasers and laser optics : Semiconductor lasers
(240.6680) Optics at surfaces : Surface plasmons
(350.4238) Other areas of optics : Nanophotonics and photonic crystals

ToC Category:
Lasers and Laser Optics

History
Original Manuscript: July 19, 2011
Revised Manuscript: August 13, 2011
Manuscript Accepted: August 13, 2011
Published: September 1, 2011

Citation
Amit M. Lakhani, Myung-ki Kim, Erwin K. Lau, and Ming C. Wu, "Plasmonic crystal defect nanolaser," Opt. Express 19, 18237-18245 (2011)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-19-19-18237


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References

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  2. W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. M. Yang, X. Zhu, N. J. Gokemeijer, Y. T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009). [CrossRef]
  3. P. Alivisatos, “The use of nanocrystals in biological detection,” Nat. Biotechnol.22(1), 47–52 (2004). [CrossRef] [PubMed]
  4. H. J. Lezec, J. A. Dionne, and H. A. Atwater, “Negative refraction at visible frequencies,” Science316(5823), 430–432 (2007). [CrossRef] [PubMed]
  5. A. Artar, A. A. Yanik, and H. Altug, “Fabry–Pérot nanocavities in multilayered plasmonic crystals for enhanced biosensing,” Appl. Phys. Lett.95(5), 051105 (2009). [CrossRef]
  6. D. Miller, “Device requirements for optical interconnects to silicon chips,” Proc. IEEE97(7), 1166–1185 (2009). [CrossRef]
  7. J. A. Dionne, L. A. Sweatlock, M. T. Sheldon, A. P. Alivisatos, and H. A. Atwater, “Silicon-based plasmonics for on-chip photonics,” IEEE J. Sel. Top. Quantum Electron.16(1), 295–306 (2010). [CrossRef]
  8. R. F. Oulton, V. J. Sorger, D. A. Genov, D. F. P. Pile, and X. Zhang, “A hybrid plasmonic waveguide for subwavelength confinement and long-range propagation,” Nat. Photonics2(8), 496–500 (2008). [CrossRef]
  9. H. T. Miyazaki and Y. Kurokawa, “Controlled plasmon resonance in closed metal/insulator/metal nanocavities,” Appl. Phys. Lett.89(21), 211126 (2006). [CrossRef]
  10. V. J. Sorger, R. F. Oulton, J. Yao, G. Bartal, and X. Zhang, “Plasmonic Fabry-Pérot nanocavity,” Nano Lett.9(10), 3489–3493 (2009). [CrossRef] [PubMed]
  11. S. I. Bozhevolnyi, V. S. Volkov, E. Devaux, J.-Y. Laluet, and T. W. Ebbesen, “Channel plasmon subwavelength waveguide components including interferometers and ring resonators,” Nature440(7083), 508–511 (2006). [CrossRef] [PubMed]
  12. D. F. P. Pile and D. K. Gramotnev, “Adiabatic and nonadiabatic nanofocusing of plasmons by tapered gap plasmon waveguides,” Appl. Phys. Lett.89(4), 041111 (2006). [CrossRef]
  13. S. Vedantam, H. Lee, J. Tang, J. Conway, M. Staffaroni, and E. Yablonovitch, “A plasmonic dimple lens for nanoscale focusing of light,” Nano Lett.9(10), 3447–3452 (2009). [CrossRef] [PubMed]
  14. M. T. Hill, Y.-S. Oei, B. Smalbrugge, Y. Zhu, T. de Vries, P. J. van Veldhoven, F. W. M. van Otten, T. J. Eijkemans, J. P. Turkiewicz, H. de Waardt, E. J. Geluk, S.-H. Kwon, Y.-H. Lee, R. Notzel, and M. K. Smit, “Lasing in metallic-coated nanocavities,” Nat. Photonics1(10), 589–594 (2007). [CrossRef]
  15. M. T. Hill, M. Marell, E. S. P. Leong, B. Smalbrugge, Y. Zhu, M. Sun, P. J. van Veldhoven, E. J. Geluk, F. Karouta, Y.-S. Oei, R. Nötzel, C.-Z. Ning, and M. K. Smit, “Lasing in metal-insulator-metal sub-wavelength plasmonic waveguides,” Opt. Express17(13), 11107–11112 (2009). [CrossRef] [PubMed]
  16. M. A. Noginov, G. Zhu, A. M. Belgrave, R. Bakker, V. M. Shalaev, E. E. Narimanov, S. Stout, E. Herz, T. Suteewong, and U. Wiesner, “Demonstration of a spaser-based nanolaser,” Nature460(7259), 1110–1112 (2009). [CrossRef] [PubMed]
  17. R. F. Oulton, V. J. Sorger, T. Zentgraf, R.-M. Ma, C. Gladden, L. Dai, G. Bartal, and X. Zhang, “Plasmon lasers at deep subwavelength scale,” Nature461(7264), 629–632 (2009). [CrossRef] [PubMed]
  18. K. Yu, A. Lakhani, and M. C. Wu, “Subwavelength metal-optic semiconductor nanopatch lasers,” Opt. Express18(9), 8790–8799 (2010). [CrossRef] [PubMed]
  19. M. P. Nezhad, A. Simic, O. Bondarenko, B. Slutsky, A. Mizrahi, L. Feng, V. Lomakin, and Y. Fainman, “Room-temperature subwavelength metallo-dielectric lasers,” Nat. Photonics4(6), 395–399 (2010). [CrossRef]
  20. C.-Y. Lu, S.-W. Chang, S. L. Chuang, T. D. Germann, and D. Bimberg, “Metal-cavity surface-emitting microlaser at room temperature,” Appl. Phys. Lett.96(25), 251101 (2010). [CrossRef]
  21. S.-H. Kwon, J.-H. Kang, C. Seassal, S.-K. Kim, P. Regreny, Y.-H. Lee, C. M. Lieber, and H.-G. Park, “Subwavelength plasmonic lasing from a semiconductor nanodisk with silver nanopan cavity,” Nano Lett.10(9), 3679–3683 (2010). [CrossRef] [PubMed]
  22. A. M. Lakhani, K. Yu, and M. C. Wu, “Lasing in subwavelength semiconductor nanopatches,” Semicond. Sci. Technol.26(1), 014013 (2011). [CrossRef]
  23. R.-M. Ma, R. F. Oulton, V. J. Sorger, G. Bartal, and X. Zhang, “Room-temperature sub-diffraction-limited plasmon laser by total internal reflection,” Nat. Mater.10(2), 110–113 (2011). [CrossRef] [PubMed]
  24. K. Ding, Z. Liu, L. Yin, H. Wang, R. Liu, M. T. Hill, M. J. H. Marell, P. J. van Veldhoven, R. Nötzel, and C. Z. Ning, “Electrical injection, continuous wave operation of subwavelength-metallic-cavity lasers at 260 K,” Appl. Phys. Lett.98(23), 231108 (2011). [CrossRef]
  25. S. L. McCall, A. F. J. Levi, R. E. Slusher, S. J. Pearton, and R. A. Logan, “Whispering-gallery mode microdisk lasers,” Appl. Phys. Lett.60(3), 289 (1992). [CrossRef]
  26. J. C. Johnson, H.-J. Choi, K. P. Knutsen, R. D. Schaller, P. Yang, and R. J. Saykally, “Single gallium nitride nanowire lasers,” Nat. Mater.1(2), 106–110 (2002). [CrossRef] [PubMed]
  27. Z. Zhang, L. Yang, V. Liu, T. Hong, K. Vahala, and A. Scherer, “Visible submicron microdisk lasers,” Appl. Phys. Lett.90(11), 111119 (2007). [CrossRef]
  28. S. Reitzenstein, T. Heindel, C. Kistner, A. Rahimi-Iman, C. Schneider, S. Hofling, and A. Forchel, “Low threshold electrically pumped quantum dot-micropillar lasers,” Appl. Phys. Lett.93(6), 061104 (2008). [CrossRef]
  29. M.-K. Kim, S. H. Lee, M. Choi, B.-H. Ahn, N. Park, Y.-H. Lee, and B. Min, “Low-loss surface-plasmonic nanobeam cavities,” Opt. Express18(11), 11089–11096 (2010). [CrossRef] [PubMed]
  30. O. Painter, R. K. Lee, A. Scherer, A. Yariv, J. D. O’Brien, P. D. Dapkus, and I. Kim, “Two-dimensional photonic band-Gap defect mode laser,” Science284(5421), 1819–1821 (1999). [CrossRef] [PubMed]
  31. H.-G. Park, S.-H. Kim, S.-H. Kwon, Y.-G. Ju, J.-K. Yang, J.-H. Baek, S.-B. Kim, and Y.-H. Lee, “Electrically driven single-cell photonic crystal laser,” Science305(5689), 1444–1447 (2004). [CrossRef] [PubMed]
  32. H. Matsubara, S. Yoshimoto, H. Saito, Y. Jianglin, Y. Tanaka, and S. Noda, “GaN photonic-crystal surface-emitting laser at blue-violet wavelengths,” Science319(5862), 445–447 (2008). [CrossRef] [PubMed]
  33. Y. Kurosaka, S. Iwahashi, Y. Liang, K. Sakai, E. Miyai, W. Kunishi, D. Ohnishi, and S. Noda, “On-chip beam-steering photonic-crystal lasers,” Nat. Photonics4(7), 447–450 (2010). [CrossRef]
  34. Y. Gong, B. Ellis, G. Shambat, T. Sarmiento, J. S. Harris, and J. Vuckovic, “Nanobeam photonic crystal cavity quantum dot laser,” Opt. Express18(9), 8781–8789 (2010). [CrossRef] [PubMed]
  35. T. Okamoto, F. H’Dhili, and S. Kawata, “Towards plasmonic band gap laser,” Appl. Phys. Lett.85(18), 3968 (2004). [CrossRef]
  36. E. K. Lau, A. Lakhani, R. S. Tucker, and M. C. Wu, “Enhanced modulation bandwidth of nanocavity light emitting devices,” Opt. Express17(10), 7790–7799 (2009). [CrossRef] [PubMed]
  37. C. Jeppesen, N. A. Mortensen, and A. Kristensen, “The effect of Ti and ITO adhesion layers on gold split-ring resonators,” Appl. Phys. Lett.97(26), 263103 (2010). [CrossRef]

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