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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 17, Iss. 23 — Nov. 9, 2009
  • pp: 20747–20755
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Vertical Plasmonic Mach-Zehnder interferometer for sensitive optical sensing

Qiaoqiang Gan, Yongkang Gao, and Filbert J. Bartoli  »View Author Affiliations


Optics Express, Vol. 17, Issue 23, pp. 20747-20755 (2009)
http://dx.doi.org/10.1364/OE.17.020747


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Abstract

Vertical plasmonic Mach-Zehnder Interferometers are investigated theoretically and experimentally, and their potential for ultra-sensitive optical sensing is discussed. Plasmonic interferences arise from coherently coupled pairs of subwavelength slits, illuminated by a broadband optical source, and this interference modulates the intensity of the far-field scattering spectrum. Experimental results, obtained using a simple experimental setup, are presented to validate theoretically predicted interferences introduced by the surface plasmon modes on top and bottom surfaces of a metal film. By observing the wavelength shift of the peaks or valleys of the interference pattern, this highly compact device has the potential to achieve a very high sensitivity relative to other nanoplasmonic architectures reported.

© 2009 OSA

1. Introduction

Surface Plasmons (SPs) are coherent oscillations of conduction electrons on a metal surface excited by electromagnetic radiation at the metal-dielectric interface. The sensitivity of the Surface Plasmon Resonance (SPR) to the refractive index change at a flat metal interface has led to the development of SPR sensing systems, which typically use prisms to couple light into a single surface-plasmon mode on a flat, continuous metal film (typically gold) [1

1. J. Homola, “Surface plasmon resonance sensors for detection of chemical and biological species,” Chem. Rev. 108(2), 462–493 ( 2008). [CrossRef] [PubMed]

]. However the intrinsic size of these experimental systems is a disadvantage for applications requiring integrated, low-cost, compact, image-based devices for portable, rapid bioanalytical measurements. Nanoplasmonic biosensors, employing nanoscale metal particles and nanostructured hole arrays, slits or gratings, and other novel topographies, could be an attractive miniaturized platform for sensitive, label-free monitoring of cellular processes [1

1. J. Homola, “Surface plasmon resonance sensors for detection of chemical and biological species,” Chem. Rev. 108(2), 462–493 ( 2008). [CrossRef] [PubMed]

3

3. J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao, and R. P. Van Duyne, “Biosensing with plasmonic nanosensors,” Nat. Mater. 7(6), 442–453 ( 2008). [CrossRef] [PubMed]

]. When receptor molecules are immobilized on the nanostructured metal surface, the binding of target biomolecules changes the local refractive index, affecting the optical properties of the SP modes and permitting optical detection [4

4. M. E. Stewart, N. H. Mack, V. Malyarchuk, J. A. N. Soares, T. W. Lee, S. K. Gray, R. G. Nuzzo, and J. A. Rogers, “Quantitative multispectral biosensing and 1D imaging using quasi-3D plasmonic crystals,” Proc. Natl. Acad. Sci. U.S.A. 103(46), 17143–17148 ( 2006). [CrossRef] [PubMed]

,5

5. J. C. Yang, J. Ji, J. M. Hogle, and D. N. Larson, “Metallic nanohole arrays on fluoropolymer substrates as small label-free real-time bioprobes,” Nano Lett. 8(9), 2718–2724 ( 2008). [CrossRef] [PubMed]

]. Recent advances in nanofabrication, nanomaterial synthesis, and nanocharacterization permit significant advances over conventional SPR evanescent wave-based biosensors, whose large size limits their effectiveness for probing nanovolumes and single cells, and for integration into microfluidic platforms. In recent years, periodic nanoplasmonic structures have been successfully employed in biosensing applications [4

4. M. E. Stewart, N. H. Mack, V. Malyarchuk, J. A. N. Soares, T. W. Lee, S. K. Gray, R. G. Nuzzo, and J. A. Rogers, “Quantitative multispectral biosensing and 1D imaging using quasi-3D plasmonic crystals,” Proc. Natl. Acad. Sci. U.S.A. 103(46), 17143–17148 ( 2006). [CrossRef] [PubMed]

15

15. J. Ji, J. C. Yang, and D. N. Larson, “Nanohole arrays of mixed designs and microwriting for simultaneous and multiple protein binding studies,” Biosens. Bioelectron. 24(9), 2847–2852 ( 2009). [CrossRef] [PubMed]

]. However, the sensitivities for these nanoplasmonic structures reported to date are much lower (two to three orders of magnitude) than other sensitive optical sensing technologies [1

1. J. Homola, “Surface plasmon resonance sensors for detection of chemical and biological species,” Chem. Rev. 108(2), 462–493 ( 2008). [CrossRef] [PubMed]

,4

4. M. E. Stewart, N. H. Mack, V. Malyarchuk, J. A. N. Soares, T. W. Lee, S. K. Gray, R. G. Nuzzo, and J. A. Rogers, “Quantitative multispectral biosensing and 1D imaging using quasi-3D plasmonic crystals,” Proc. Natl. Acad. Sci. U.S.A. 103(46), 17143–17148 ( 2006). [CrossRef] [PubMed]

15

15. J. Ji, J. C. Yang, and D. N. Larson, “Nanohole arrays of mixed designs and microwriting for simultaneous and multiple protein binding studies,” Biosens. Bioelectron. 24(9), 2847–2852 ( 2009). [CrossRef] [PubMed]

]. Consequently, increasing the sensitivity of nanoplasmonic biosensors is essential to their integration into practical devices and achieving significant impact on the future markets.

Interferometry is one of the most sensitive optical interrogation methods and has been used to screen molecular interactions in surface binding modes. Examples include fluorescence interferometry for high resolution microscopy or nanoscopy [16

16. D. Braun and P. Fromherz, “Fluorescence interferometry of neuronal cell adhesion on microstructured silicon,” Phys. Rev. Lett. 81(23), 5241–5244 ( 1998). [CrossRef]

20

20. G. Shtengel, J. A. Galbraith, C. G. Galbraith, J. Lippincott-Schwartz, J. M. Gillette, S. Manley, R. Sougrat, C. M. Waterman, P. Kanchanawong, M. W. Davidson, R. D. Fetter, and H. F. Hess, “Interferometric fluorescent super-resolution microscopy resolves 3D cellular ultrastructure,” Proc. Natl. Acad. Sci. U.S.A. 106(9), 3125–3130 ( 2009). [CrossRef] [PubMed]

], label-free sensing based on the Mach-Zehnder Interferometer (MZI) [21

21. F. Brosinger, H. Freimuth, M. Lacher, W. Ehrfeld, E. Gedig, A. Katerkamp, F. Spener, and K. Cammann, “A label-free affinity sensor with compensation of unspecific protein interaction by a highly sensitive integrated optical Mach–Zehnder interferometer on silicon,” Sens. Actuators B Chem. 44(1-3), 350–355 ( 1997). [CrossRef]

24

24. E. F. Schipper, A. M. Brugman, L. M. Lechuga, R. P. H. Kooyman, J. Greve, and C. Dominguez, “The realization of an integrated Mach-Zehnder waveguide immunosensor in silicon technology,” Sens. Actuators B Chem. 40(2-3), 147–153 ( 1997). [CrossRef]

], Young Interferometer [25

25. A. Ymeti, J. S. Kanger, J. Greve, P. V. Lambeck, R. Wijn, and R. G. Heideman, “Realization of a multichannel integrated Young interferometer chemical sensor,” Appl. Opt. 42(28), 5649–5660 ( 2003). [CrossRef] [PubMed]

], dual polarization interferometer [26

26. M. J. Swann, L. L. Peel, S. Carrington, and N. J. Freeman, “Dual-polarization interferometry: an analytical technique to measure changes in protein structure in real time, to determine the stoichiometry of binding events, and to differentiate between specific and nonspecific interactions,” Anal. Biochem. 329(2), 190–198 ( 2004). [CrossRef] [PubMed]

], back-scattering interferometry [27

27. D. J. Bornhop, J. C. Latham, A. Kussrow, D. A. Markov, R. D. Jones, and H. S. Sørensen, “Free-solution, label-free molecular interactions studied by back-scattering interferometry,” Science 317(5845), 1732–1736 ( 2007). [CrossRef] [PubMed]

], and spectral reflectance interferometry [28

28. E. Ozkumur, J. W. Needham, D. A. Bergstein, R. Gonzalez, M. Cabodi, J. M. Gershoni, B. B. Goldberg, and M. S. Unlü, “Label-free and dynamic detection of biomolecular interactions for high-throughput microarray applications,” Proc. Natl. Acad. Sci. U.S.A. 105(23), 7988–7992 ( 2008). [CrossRef] [PubMed]

], etc. Recently, surface plasmon interferometry was also proposed [29

29. H. F. Schouten, N. Kuzmin, G. Dubois, T. D. Visser, G. Gbur, P. F. Alkemade, H. Blok, G. W. Hooft, D. Lenstra, and E. R. Eliel, “Plasmon-assisted two-slit transmission: Young’s experiment revisited,” Phys. Rev. Lett. 94(5), 053901 ( 2005). [CrossRef] [PubMed]

,30

30. V. V. Temnov, U. Woggon, J. Dintinger, E. Devaux, and T. W. Ebbesen, “Surface Plasmon interferometry: measuring group velocity of surface plasmons,” Optim. Lett. 32(10), 1235 ( 2007). [CrossRef]

], and is believed to be promising for sensitive lable-free sensing applications [31

31. X. Wu, J. Zhang, J. Chen, C. Zhao, and Q. Gong, “Refractive index sensor based on surface-plasmon interference,” Optim. Lett. 34(3), 392 ( 2009). [CrossRef]

].

In this article, we propose a vertical plasmonic Mach-Zehnder interferometer (VPMZI) for sensitive optical sensing. The paper is organized as follows. We first investigate the principle of operation for the VPMZI in section 2. Section 3 presents analytical calculations and numerical simulations, and discusses how high sensitivity may be achieved by combining SP modes with the MZI concept. We show that the sensitivity of compact biosensing devices could be enhanced significantly relative to other nanoplasmonic architectures reported [4

4. M. E. Stewart, N. H. Mack, V. Malyarchuk, J. A. N. Soares, T. W. Lee, S. K. Gray, R. G. Nuzzo, and J. A. Rogers, “Quantitative multispectral biosensing and 1D imaging using quasi-3D plasmonic crystals,” Proc. Natl. Acad. Sci. U.S.A. 103(46), 17143–17148 ( 2006). [CrossRef] [PubMed]

15

15. J. Ji, J. C. Yang, and D. N. Larson, “Nanohole arrays of mixed designs and microwriting for simultaneous and multiple protein binding studies,” Biosens. Bioelectron. 24(9), 2847–2852 ( 2009). [CrossRef] [PubMed]

] when the refractive indices at the top and bottom surfaces of the metal film are closely matched. To complement the theoretical investigations, we present in section 4 experimental observation of the spectral interference introduced by the VPMZI. The experimental apparatus is relatively simple, and the measured results indicate that SPP modes at the top and bottom surfaces do interfere with each other and have the potential to achieve high sensitivity to the surface refractive index change. Finally, conclusions and potential applications of the VPMZI are presented in Section 5.

2. VPMZI Constructed by double slits on a metal film

The phase modulation properties of this novel VPMZI are sensitive to changes in the refractive index in the sensing arm (top surface) relative to that in the reference arm (bottom surface). When the refractive index of the sensing arm, n1, is changed to n1 + Δn1, the phase change is given by the expression
Δϕ=2πLλ(εm'(λ)n12εm'(λ)+n12εm'(λ)(n1+Δn1)2εm'(λ)+(n1+Δn1)2)
(1)
which relates the phase change to the change in refractive index. In our calculations, an incident wavelength of 1033nm is employed, for which the permittivity of silver is −48.81 + i3.16 [33

33. E. D. Palik, Handbook of Optical Constants of Solids (Aacademic, Orlando, LF, 1985), Vol. 1.

]. We assume that the dielectric material on the sensing surface is water (n1 = 1.33) and the slit separation distance, L, is 70μm. As shown in Fig. 1, a refractive index change of 0.1 may introduce a phase change of about 7.2(2π), which is in a good agreement with the two-dimensional (2D) finite-difference-time-domain (FDTD) modeling result shown in the lower inset of Fig. 1. Based on the FDTD modeling result, more than 7 periods of the interference pattern can be observed in the far-field scattering signal, which can be utilized in optical sensing applications. However, the length of the sensing arm for this metal structure must be kept short due to the intrinsic loss of metals. Consequently, the phase-change sensitivity of this metallic MZI [~72(2π)/RIU] is much lower than Si-based MZI devices with very long sensing arms [21

21. F. Brosinger, H. Freimuth, M. Lacher, W. Ehrfeld, E. Gedig, A. Katerkamp, F. Spener, and K. Cammann, “A label-free affinity sensor with compensation of unspecific protein interaction by a highly sensitive integrated optical Mach–Zehnder interferometer on silicon,” Sens. Actuators B Chem. 44(1-3), 350–355 ( 1997). [CrossRef]

24

24. E. F. Schipper, A. M. Brugman, L. M. Lechuga, R. P. H. Kooyman, J. Greve, and C. Dominguez, “The realization of an integrated Mach-Zehnder waveguide immunosensor in silicon technology,” Sens. Actuators B Chem. 40(2-3), 147–153 ( 1997). [CrossRef]

]. For example, the phase-change sensitivity of a Si-based MZI with a 5mm sensing arm was reported to be about 1400(2π)/RIU [24

24. E. F. Schipper, A. M. Brugman, L. M. Lechuga, R. P. H. Kooyman, J. Greve, and C. Dominguez, “The realization of an integrated Mach-Zehnder waveguide immunosensor in silicon technology,” Sens. Actuators B Chem. 40(2-3), 147–153 ( 1997). [CrossRef]

].

3. Achieving high sensitivity by matching the refractive indices at the two surfaces

Besides the phase modulation at a single wavelength, such double-slit or slit-groove metal structures have also been reported to exhibit spectral interference when the input is a broad band light source [29

29. H. F. Schouten, N. Kuzmin, G. Dubois, T. D. Visser, G. Gbur, P. F. Alkemade, H. Blok, G. W. Hooft, D. Lenstra, and E. R. Eliel, “Plasmon-assisted two-slit transmission: Young’s experiment revisited,” Phys. Rev. Lett. 94(5), 053901 ( 2005). [CrossRef] [PubMed]

31

31. X. Wu, J. Zhang, J. Chen, C. Zhao, and Q. Gong, “Refractive index sensor based on surface-plasmon interference,” Optim. Lett. 34(3), 392 ( 2009). [CrossRef]

]. In this section, we discuss how that the spectral interference supported by this proposed VPMZI can lead to an high sensitivity, significantly better than that reported for other nanoplasmonic architectures [4

4. M. E. Stewart, N. H. Mack, V. Malyarchuk, J. A. N. Soares, T. W. Lee, S. K. Gray, R. G. Nuzzo, and J. A. Rogers, “Quantitative multispectral biosensing and 1D imaging using quasi-3D plasmonic crystals,” Proc. Natl. Acad. Sci. U.S.A. 103(46), 17143–17148 ( 2006). [CrossRef] [PubMed]

15

15. J. Ji, J. C. Yang, and D. N. Larson, “Nanohole arrays of mixed designs and microwriting for simultaneous and multiple protein binding studies,” Biosens. Bioelectron. 24(9), 2847–2852 ( 2009). [CrossRef] [PubMed]

,32

32. M. H. Lee, H. Gao, and T. W. Odom, “Refractive index sensing using quasi one-dimensional nanoslit arrays,” Nano Lett. 9(7), 2584–2588 ( 2009). [CrossRef] [PubMed]

].

When the refractive index of the dielectric top layer is changed, the peaks and valleys in the interference pattern will shift accordingly. The sensitivity could be approximately derived by setting the term.2πLλ(εm'(λ)n12εm'(λ)+n12εm'(λ)n22εm'(λ)+n22).to be constant, yielding [31

31. X. Wu, J. Zhang, J. Chen, C. Zhao, and Q. Gong, “Refractive index sensor based on surface-plasmon interference,” Optim. Lett. 34(3), 392 ( 2009). [CrossRef]

]:
S=ΔλΔn=λn13(εm'(λ)n12εm'(λ)+n12)3/2/(εm'(λ)n12εm'(λ)+n12εm'(λ)n22εm'(λ)+n22)
(2)
From Eq. (2), it is seen that when the n1 < n2, the sensitivity parameter is negative, indicating that the interference pattern will shift to shorter wavelengths, whereas if n1 > n2, the sensitivity value is positive, indicating that the interference pattern will shift to longer wavelengths. More importantly, this equation indicates that the sensitivity increases greatly if the two terms in the denominator are close in value. Figure 2
Fig. 2 Theoretical sensitivity (absolute value) of the VPMZI obtained by Eq. (1). The thickness of the Au film is 200nm. The gap between the two slits is 70μm, and the width of each slit is 400nm. In this calculation, the refractive index for the top layer is 1.33.
illustrates the sensitivities that could potentially be achieved by varying the refractive index of the substrate material below the metal surface. In this calculation, we assume the metal film is gold and the top dielectric layer is water (n1 = 1.33). As an example, when n2 = 1.51, the relation between the sensitivity and the operating wavelength is shown by the lowest curve in Fig. 2. These simulation parameters, which are similar to the measurement conditions employed in ref [31

31. X. Wu, J. Zhang, J. Chen, C. Zhao, and Q. Gong, “Refractive index sensor based on surface-plasmon interference,” Optim. Lett. 34(3), 392 ( 2009). [CrossRef]

], yielded a sensitivity of approximately 4718nm/RIU at approximately 860nm. This value is in close agreement with experimental value of 4547nm/RIU reported in ref [31

31. X. Wu, J. Zhang, J. Chen, C. Zhao, and Q. Gong, “Refractive index sensor based on surface-plasmon interference,” Optim. Lett. 34(3), 392 ( 2009). [CrossRef]

]. Based on Eq. (2), Wu et. al. noted that higher sensitivities can be achieved at longer wavelengths [31

31. X. Wu, J. Zhang, J. Chen, C. Zhao, and Q. Gong, “Refractive index sensor based on surface-plasmon interference,” Optim. Lett. 34(3), 392 ( 2009). [CrossRef]

]. However, this approach to improving performance is limited by strong water absorption in the near-infrared spectral region. Another obvious approach to enhance the sensitivity, not emphasized in ref [31

31. X. Wu, J. Zhang, J. Chen, C. Zhao, and Q. Gong, “Refractive index sensor based on surface-plasmon interference,” Optim. Lett. 34(3), 392 ( 2009). [CrossRef]

], can be realized when the refractive index of the substrate, n2, is decreased, approaching that of the top layer, n1, as illustrated by the series of curves in Fig. 2.

The most important design requirement for a sensitive VPMZI is to match the ERI at the top and bottom interfaces. The ideal structure to meet the ERI matching condition is the one where the dispersion curve at the top surface is very close to that at the bottom interface, indicating that the ERI match condition could be met over a broad range of wavelengths. This can in principle be accomplished by finding a substrate whose refractive index is close to the liquid on the top. For example, the authors in ref [5

5. J. C. Yang, J. Ji, J. M. Hogle, and D. N. Larson, “Metallic nanohole arrays on fluoropolymer substrates as small label-free real-time bioprobes,” Nano Lett. 8(9), 2718–2724 ( 2008). [CrossRef] [PubMed]

] employed the fluorinated ethylene propylene copolymer (FEP) as a replica substrate because it is chemically inert, thermoplastic, transparent in the visible region, and has a refractive index of 1.341 at the λ of 590 nm. Here we employ the 2D FDTD method to simulate the sensitivity for a Au structure on substrates with various values of refractive index. The computational setup is shown in the upper inset in Fig. 1, the separation between the two slits is 70μm. Only one slit is illuminated by the incident light. The scattered light from the other slit is monitored. One can calculate the sensitivity from the shift in the peak or valley wavelength. For example, consider n2 = 1.46. When n1 changes from 1.33 to 1.331, the peak of the interference pattern at 970nm will shift to 964nm, indicating that the sensitivity is −0.6X104 nm/RIU [see the upper panel in Fig. 3(a)
Fig. 3 Numerical modeling for the interference signal of the scattered light from the slit on the Au film shown in Fig. 1 (a). The refractive indices of the substrates are 1.46 (a), 1.36 (b) and 1.35 (c), respectively. The gap between the two slits is fixed to be 70μm. The upper panels are FDTD modeling results, and the lower panels are results obtained using the term cos[2πLλ(εm'(λ)n12εm'(λ)+n12εm'(λ)n22εm'(λ)+n22)].
]. If n2 is instead set to 1.36, the valley of the interference pattern at 940nm will shift to 908nm, indicating a sensitivity of about −3.2X104nm/RIU. Similarly, the peak at 1168nm will shift to 1132nm, indicating a sensitivity of about −3.6X104nm/RIU [see the upper panel in Fig. 3(b)]. When n2 is further decreased to 1.35, the valley position at 1076nm will shift to 1034nm, indicating a sensitivity of −4.2X104nm/RIU. At the same time, the peak at 1582nm will shift to 1486nm, indicating a sensitivity of about −9.2X104nm/RIU [see the upper panel in Fig. 3(c)]. Using the interference expression, 2πLλ(εm'(λ)n12εm'(λ)+n12εm'(λ)n22εm'(λ)+n22), the theoretical spectral interference pattern of this structure was calculated and plotted in the lower panels in Fig. 3, which is in reasonably good agreement with the FDTD modeling result. Remarkably, the sensitivities shown in Fig. 3 (b) and (c) are between one and two orders of magnitude larger than the best sensitivity reported for nanohole arrays in ref [11

11. G. M. Hwang, L. Pang, E. H. Mullen, and Y. Fainman, “Plasmonic sensing of biological analytes through nanoholes,” IEEE Sens. J. 8(12), 2074–2079 ( 2008). [CrossRef]

] (about 1500nm/RIU).

If a low refractive index substrate is unavailable, the ERI matching condition can also be met by various surface dispersion engineering approaches. For example, one can introduce a thin film of dielectric material with a higher refractive index on top of the metal surface to tune the ERI of this interface. Various nanopatterned structures, such as periodic metal-dielectric-air grooves [34

34. Z. Fu, Q. Gan, K Gao, G Wang, Z Pan, and F Bartoli,. “Numerical Investigation of a Bidirectional Wave Coupler Based on Surface Plasmonic Polarition Bragg Gratings in Near Infrared Spectrum,” J. Lightwave Technol. 26, 3699 ( 2008). [CrossRef]

] and surface grating structures [35

35. Q. Gan, Z. Fu, Y. J. Ding, and F. J. Bartoli, “Ultrawide-bandwidth slow-light system based on THz plasmonic graded metal grating structures,” Phys. Rev. Lett. 100(25), 256803 ( 2008). [CrossRef] [PubMed]

,36

36. Q. Gan, Y. J. Ding, and F. J. Bartoli, “Rainbow” trapping and releasing at telecommunication wavelengths,” Phys. Rev. Lett. 102(5), 056801 ( 2009). [CrossRef] [PubMed]

], could also be employed to finely tune the shape of the dispersion curve and approach to the ERI match condition. In addition to optimizing the sensitivity, other important factors should be considered, such as fluctuations in the refractive index induced by changes in temperature, which were not considered in this theoretical study. Considering that the temperature induced refractive index changes for SiO2 substrates and metals are smaller than that for Si-based waveguides, the temperature performance of this plasmonic MZI is expected to be better than Si-based MZI devices. This will be studied further in future investigations.

4. Experimental validation of the spectral interference in the VPMZI

5. Conclusion

In conclusion, this work demonstrates the feasibility of the VPMZI with very high sensitivity for optical sensing, and a potential one-to-two orders-of-magnitude improvement over previously reported nanoaperture arrays. Plasmonic interferences arise from coherently coupled pairs of subwavelength slits, illuminated from below by an optical beam, and this interference modulates the intensity of the far-field scattering. A simple experiment setup is also presented to observe the spectral interference introduced by the SPP modes from the two surfaces. Important advantages of this design were discussed, including the vertical MZI structure, in which the sensing branch is on top of the metal-liquid interface, and the reference branch is on the bottom interface. The gap between these two branches is only tens or hundreds of nanometers, which is promising for novel integrated sensitive biosensing platforms and subwavelength optics on-a-chip.

Acknowledgment

The authors would like to acknowledge the support of this research by NSF (Award # 0901324).

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A. Bilenca, J. Cao, M. Colice, A. Ozcan, B. Bouma, L. Raftery, and G. Tearney, “Fluorescence interferometry: principles and applications in biology,” Ann. N. Y. Acad. Sci. 1130(1), 68–77 ( 2008). [CrossRef] [PubMed]

19.

M. Dogan, A. Yalcin, S. Jain, M. B. Goldberg, A. K. Swan, M. S. Unlu, and B. B. Goldberg, “Spectral Self-Interference Fluorescence Microscopy for Subcellular Imaging,” IEEE J. Sel. Top. Quantum Electron. 14(1), 217–225 ( 2008). [CrossRef]

20.

G. Shtengel, J. A. Galbraith, C. G. Galbraith, J. Lippincott-Schwartz, J. M. Gillette, S. Manley, R. Sougrat, C. M. Waterman, P. Kanchanawong, M. W. Davidson, R. D. Fetter, and H. F. Hess, “Interferometric fluorescent super-resolution microscopy resolves 3D cellular ultrastructure,” Proc. Natl. Acad. Sci. U.S.A. 106(9), 3125–3130 ( 2009). [CrossRef] [PubMed]

21.

F. Brosinger, H. Freimuth, M. Lacher, W. Ehrfeld, E. Gedig, A. Katerkamp, F. Spener, and K. Cammann, “A label-free affinity sensor with compensation of unspecific protein interaction by a highly sensitive integrated optical Mach–Zehnder interferometer on silicon,” Sens. Actuators B Chem. 44(1-3), 350–355 ( 1997). [CrossRef]

22.

F. Prieto, B. Sepulveda, A. Calle, and A LloberaC Dominguez, A Abad, A Montoya, and L. M Lechuga, “An integrated optical interferometric nanodevice based on silicon technology for biosensor applications,” Nanotechnology 14(8), 907–912 ( 2003). [CrossRef]

23.

F. Prieto, B. Sepulveda, A. Calle, A. Llobera, C. Dommguez, and L. M. Lechuga, “Integrated Mach–Zehnder interferometer based on ARROW structures for biosensor applications,” Sens. Actuators B Chem. 92(1-2), 151–158 ( 2003). [CrossRef]

24.

E. F. Schipper, A. M. Brugman, L. M. Lechuga, R. P. H. Kooyman, J. Greve, and C. Dominguez, “The realization of an integrated Mach-Zehnder waveguide immunosensor in silicon technology,” Sens. Actuators B Chem. 40(2-3), 147–153 ( 1997). [CrossRef]

25.

A. Ymeti, J. S. Kanger, J. Greve, P. V. Lambeck, R. Wijn, and R. G. Heideman, “Realization of a multichannel integrated Young interferometer chemical sensor,” Appl. Opt. 42(28), 5649–5660 ( 2003). [CrossRef] [PubMed]

26.

M. J. Swann, L. L. Peel, S. Carrington, and N. J. Freeman, “Dual-polarization interferometry: an analytical technique to measure changes in protein structure in real time, to determine the stoichiometry of binding events, and to differentiate between specific and nonspecific interactions,” Anal. Biochem. 329(2), 190–198 ( 2004). [CrossRef] [PubMed]

27.

D. J. Bornhop, J. C. Latham, A. Kussrow, D. A. Markov, R. D. Jones, and H. S. Sørensen, “Free-solution, label-free molecular interactions studied by back-scattering interferometry,” Science 317(5845), 1732–1736 ( 2007). [CrossRef] [PubMed]

28.

E. Ozkumur, J. W. Needham, D. A. Bergstein, R. Gonzalez, M. Cabodi, J. M. Gershoni, B. B. Goldberg, and M. S. Unlü, “Label-free and dynamic detection of biomolecular interactions for high-throughput microarray applications,” Proc. Natl. Acad. Sci. U.S.A. 105(23), 7988–7992 ( 2008). [CrossRef] [PubMed]

29.

H. F. Schouten, N. Kuzmin, G. Dubois, T. D. Visser, G. Gbur, P. F. Alkemade, H. Blok, G. W. Hooft, D. Lenstra, and E. R. Eliel, “Plasmon-assisted two-slit transmission: Young’s experiment revisited,” Phys. Rev. Lett. 94(5), 053901 ( 2005). [CrossRef] [PubMed]

30.

V. V. Temnov, U. Woggon, J. Dintinger, E. Devaux, and T. W. Ebbesen, “Surface Plasmon interferometry: measuring group velocity of surface plasmons,” Optim. Lett. 32(10), 1235 ( 2007). [CrossRef]

31.

X. Wu, J. Zhang, J. Chen, C. Zhao, and Q. Gong, “Refractive index sensor based on surface-plasmon interference,” Optim. Lett. 34(3), 392 ( 2009). [CrossRef]

32.

M. H. Lee, H. Gao, and T. W. Odom, “Refractive index sensing using quasi one-dimensional nanoslit arrays,” Nano Lett. 9(7), 2584–2588 ( 2009). [CrossRef] [PubMed]

33.

E. D. Palik, Handbook of Optical Constants of Solids (Aacademic, Orlando, LF, 1985), Vol. 1.

34.

Z. Fu, Q. Gan, K Gao, G Wang, Z Pan, and F Bartoli,. “Numerical Investigation of a Bidirectional Wave Coupler Based on Surface Plasmonic Polarition Bragg Gratings in Near Infrared Spectrum,” J. Lightwave Technol. 26, 3699 ( 2008). [CrossRef]

35.

Q. Gan, Z. Fu, Y. J. Ding, and F. J. Bartoli, “Ultrawide-bandwidth slow-light system based on THz plasmonic graded metal grating structures,” Phys. Rev. Lett. 100(25), 256803 ( 2008). [CrossRef] [PubMed]

36.

Q. Gan, Y. J. Ding, and F. J. Bartoli, “Rainbow” trapping and releasing at telecommunication wavelengths,” Phys. Rev. Lett. 102(5), 056801 ( 2009). [CrossRef] [PubMed]

37.

P. Lalanne, J. P. Hugonin, and J. C. Rodier, “Approximate model for surface-plasmon generation at slit apertures,” J. Opt. Soc. Am. B 23(7), 1608 ( 2006). [CrossRef]

38.

H. W. Kihm, G. K. Lee, D. S. Kim, J. H. Kang, and P. Q. Han, “Control of surface Plasmon generation efficiency by silt-width tuning,” Appl. Phys. Lett. 92(5), 051115 ( 2008). [CrossRef]

39.

A. Drezet, A. Hohenau, A. L. Stepanov, H. Ditlbacher, B. Steinberger, N. Galler, F. R. Aussenegg, A. Leitner, and J. R. Krenn, “How to erase surface plasmon fringes,” Appl. Phys. Lett. 89(9), 091117 ( 2006). [CrossRef]

40.

P. Lalanne and J. P. Hugonin, “Interaction between optical nano-objects at metallo-dielectric interfaces,” Nat. Phys. 2(8), 551–556 ( 2006). [CrossRef]

41.

F. J. García de AbajoF. J. García de AbajoF. J Garcia de Abajo, “Light scattering by particle and hole arrays,” Rev. Mod. Phys. 79(4), 1267–1290 ( 2007). [CrossRef]

42.

J. Weiner, “The physics of light transmission through subwavelength apertures and aperture arrays,” Rep. Prog. Phys. 72(6), 064401 ( 2009). [CrossRef]

43.

P. Lalanne, J. P. Hugonin, H. T. Liu, and B. Wang, A microscopic view of the electromagnetic properties of sub-λ metallic surfaces, Surf. Sci. Rep. (2009).

OCIS Codes
(130.6010) Integrated optics : Sensors
(240.6680) Optics at surfaces : Surface plasmons
(260.3910) Physical optics : Metal optics
(310.2790) Thin films : Guided waves

ToC Category:
Sensors

History
Original Manuscript: September 29, 2009
Revised Manuscript: October 12, 2009
Manuscript Accepted: October 12, 2009
Published: October 28, 2009

Citation
Qiaoqiang Gan, Yongkang Gao, and Filbert J. Bartoli, "Vertical Plasmonic Mach-Zehnder interferometer for sensitive optical sensing," Opt. Express 17, 20747-20755 (2009)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-17-23-20747


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References

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  14. H. Im, A. Lesuffleur, N. C. Lindquist, and S. H. Oh, “Plasmonic nanoholes in a multichannel microarray format for parallel kinetic assays and differential sensing,” Anal. Chem. 81(8), 2854–2859 (2009). [CrossRef] [PubMed]
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  18. A. Bilenca, J. Cao, M. Colice, A. Ozcan, B. Bouma, L. Raftery, and G. Tearney, “Fluorescence interferometry: principles and applications in biology,” Ann. N. Y. Acad. Sci. 1130(1), 68–77 (2008). [CrossRef] [PubMed]
  19. M. Dogan, A. Yalcin, S. Jain, M. B. Goldberg, A. K. Swan, M. S. Unlu, and B. B. Goldberg, “Spectral Self-Interference Fluorescence Microscopy for Subcellular Imaging,” IEEE J. Sel. Top. Quantum Electron. 14(1), 217–225 (2008). [CrossRef]
  20. G. Shtengel, J. A. Galbraith, C. G. Galbraith, J. Lippincott-Schwartz, J. M. Gillette, S. Manley, R. Sougrat, C. M. Waterman, P. Kanchanawong, M. W. Davidson, R. D. Fetter, and H. F. Hess, “Interferometric fluorescent super-resolution microscopy resolves 3D cellular ultrastructure,” Proc. Natl. Acad. Sci. U.S.A. 106(9), 3125–3130 (2009). [CrossRef] [PubMed]
  21. F. Brosinger, H. Freimuth, M. Lacher, W. Ehrfeld, E. Gedig, A. Katerkamp, F. Spener, and K. Cammann, “A label-free affinity sensor with compensation of unspecific protein interaction by a highly sensitive integrated optical Mach–Zehnder interferometer on silicon,” Sens. Actuators B Chem. 44(1-3), 350–355 (1997). [CrossRef]
  22. F. Prieto, B. Sepulveda, A. Calle, and A LloberaC Dominguez, A Abad, A Montoya, and L. M Lechuga, “An integrated optical interferometric nanodevice based on silicon technology for biosensor applications,” Nanotechnology 14(8), 907–912 (2003). [CrossRef]
  23. F. Prieto, B. Sepulveda, A. Calle, A. Llobera, C. Dommguez, and L. M. Lechuga, “Integrated Mach–Zehnder interferometer based on ARROW structures for biosensor applications,” Sens. Actuators B Chem. 92(1-2), 151–158 (2003). [CrossRef]
  24. E. F. Schipper, A. M. Brugman, L. M. Lechuga, R. P. H. Kooyman, J. Greve, and C. Dominguez, “The realization of an integrated Mach-Zehnder waveguide immunosensor in silicon technology,” Sens. Actuators B Chem. 40(2-3), 147–153 (1997). [CrossRef]
  25. A. Ymeti, J. S. Kanger, J. Greve, P. V. Lambeck, R. Wijn, and R. G. Heideman, “Realization of a multichannel integrated Young interferometer chemical sensor,” Appl. Opt. 42(28), 5649–5660 (2003). [CrossRef] [PubMed]
  26. M. J. Swann, L. L. Peel, S. Carrington, and N. J. Freeman, “Dual-polarization interferometry: an analytical technique to measure changes in protein structure in real time, to determine the stoichiometry of binding events, and to differentiate between specific and nonspecific interactions,” Anal. Biochem. 329(2), 190–198 (2004). [CrossRef] [PubMed]
  27. D. J. Bornhop, J. C. Latham, A. Kussrow, D. A. Markov, R. D. Jones, and H. S. Sørensen, “Free-solution, label-free molecular interactions studied by back-scattering interferometry,” Science 317(5845), 1732–1736 (2007). [CrossRef] [PubMed]
  28. E. Ozkumur, J. W. Needham, D. A. Bergstein, R. Gonzalez, M. Cabodi, J. M. Gershoni, B. B. Goldberg, and M. S. Unlü, “Label-free and dynamic detection of biomolecular interactions for high-throughput microarray applications,” Proc. Natl. Acad. Sci. U.S.A. 105(23), 7988–7992 (2008). [CrossRef] [PubMed]
  29. H. F. Schouten, N. Kuzmin, G. Dubois, T. D. Visser, G. Gbur, P. F. Alkemade, H. Blok, G. W. Hooft, D. Lenstra, and E. R. Eliel, “Plasmon-assisted two-slit transmission: Young’s experiment revisited,” Phys. Rev. Lett. 94(5), 053901 (2005). [CrossRef] [PubMed]
  30. V. V. Temnov, U. Woggon, J. Dintinger, E. Devaux, and T. W. Ebbesen, “Surface Plasmon interferometry: measuring group velocity of surface plasmons,” Optim. Lett. 32(10), 1235 (2007). [CrossRef]
  31. X. Wu, J. Zhang, J. Chen, C. Zhao, and Q. Gong, “Refractive index sensor based on surface-plasmon interference,” Optim. Lett. 34(3), 392 (2009). [CrossRef]
  32. M. H. Lee, H. Gao, and T. W. Odom, “Refractive index sensing using quasi one-dimensional nanoslit arrays,” Nano Lett. 9(7), 2584–2588 (2009). [CrossRef] [PubMed]
  33. E. D. Palik, Handbook of Optical Constants of Solids (Aacademic, Orlando, LF, 1985), Vol. 1.
  34. Z. Fu, Q. Gan, K Gao, G Wang, Z Pan, and F Bartoli,. “Numerical Investigation of a Bidirectional Wave Coupler Based on Surface Plasmonic Polarition Bragg Gratings in Near Infrared Spectrum,” J. Lightwave Technol. 26, 3699 (2008). [CrossRef]
  35. Q. Gan, Z. Fu, Y. J. Ding, and F. J. Bartoli, “Ultrawide-bandwidth slow-light system based on THz plasmonic graded metal grating structures,” Phys. Rev. Lett. 100(25), 256803 (2008). [CrossRef] [PubMed]
  36. Q. Gan, Y. J. Ding, and F. J. Bartoli, “Rainbow” trapping and releasing at telecommunication wavelengths,” Phys. Rev. Lett. 102(5), 056801 (2009). [CrossRef] [PubMed]
  37. P. Lalanne, J. P. Hugonin, and J. C. Rodier, “Approximate model for surface-plasmon generation at slit apertures,” J. Opt. Soc. Am. B 23(7), 1608 (2006). [CrossRef]
  38. H. W. Kihm, G. K. Lee, D. S. Kim, J. H. Kang, and P. Q. Han, “Control of surface Plasmon generation efficiency by silt-width tuning,” Appl. Phys. Lett. 92(5), 051115 (2008). [CrossRef]
  39. A. Drezet, A. Hohenau, A. L. Stepanov, H. Ditlbacher, B. Steinberger, N. Galler, F. R. Aussenegg, A. Leitner, and J. R. Krenn, “How to erase surface plasmon fringes,” Appl. Phys. Lett. 89(9), 091117 (2006). [CrossRef]
  40. P. Lalanne and J. P. Hugonin, “Interaction between optical nano-objects at metallo-dielectric interfaces,” Nat. Phys. 2(8), 551–556 (2006). [CrossRef]
  41. F. J. García de Abajo and F. J Garcia de Abajo, “Light scattering by particle and hole arrays,” Rev. Mod. Phys. 79(4), 1267–1290 (2007). [CrossRef]
  42. J. Weiner, “The physics of light transmission through subwavelength apertures and aperture arrays,” Rep. Prog. Phys. 72(6), 064401 (2009). [CrossRef]
  43. P. Lalanne, J. P. Hugonin, H. T. Liu, and B. Wang, A microscopic view of the electromagnetic properties of sub-λ metallic surfaces, Surf. Sci. Rep. (2009).

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