[1] A. Schliesser, N. Picqué, T. W. Hänsch. Mid-infrared frequency combs. Nat. Photonics, 6, 440-449(2012).

[2] R. Maulini, I. Dunayevskiy, A. Lyakh, A. Tsekoun, C. K. N. Patel, L. Diehl, C. Pflugl, F. Capasso. Widely tunable high-power external cavity quantum cascade laser operating in continuous-wave at room temperature. Electron. Lett., 45, 107-108(2009).

[3]

[4]

[5]

[6]

[7] N. Hô, M. C. Phillips, H. Qiao, P. J. Allen, K. Krishnaswami, B. J. Riley, T. L. Myers, N. C. Anheier. Single-mode low-loss chalcogenide glass waveguides for the mid-infrared. Opt. Lett., 31, 1860-1862(2006).

[8] C. Tsay, E. Mujagić, C. K. Madsen, C. F. Gmachl, C. B. Arnold. Mid-infrared characterization of solution-processed As₂S₃ chalcogenide glass waveguides. Opt. Express, 18, 15523-15530(2010).

[9] P. Ma, D.-Y. Choi, Y. Yu, X. Gai, Z. Yang, S. Debbarma, S. Madden, B. Luther-Davies. Low-loss chalcogenide waveguides for chemical sensing in the mid-infrared. Opt. Express, 21, 29927-29937(2013).

[10] O. Eyal, V. Scharf, S. Shalem, A. Katzir. Single-mode mid-infrared silver halide planar waveguides. Opt. Lett., 21, 1147-1149(1996).

[11] B. Dekel, A. Katzir. Silver halide planar waveguides and grating couplers for middle infrared integrated optics. Appl. Phys. Lett., 97, 241106(2010).

[12] T. Lewi, A. Katzir. Silver halide single-mode strip waveguides for the mid-infrared. Opt. Lett., 37, 2733-2735(2012).

[13] P. T. Lin, V. Singh, L. Kimerling, A. M. Agarwal. Planar silicon nitride mid-infrared devices. Appl. Phys. Lett., 102, 251121(2013).

[14] K. Luke, Y. Okawachi, M. R. E. Lamont, A. L. Gaeta, M. Lipson. Broadband mid-infrared frequency comb generation in a Si₃N₄ microresonator. Opt. Lett., 40, 4823-4826(2015).

[15] T. Hu, B. Dong, X. Luo, T.-Y. Liow, J. Song, C. Lee, G.-Q. Lo. Silicon photonic platforms for mid-infrared applications [Invited]. Photon. Res., 5, 417-430(2017).

[16] C. Charlton, M. Giovannini, J. Faist, B. Mizaikoff. Fabrication and characterization of molecular beam epitaxy grown thin-film GaAs waveguides for mid-infrared evanescent field chemical sensing. Anal. Chem., 78, 4224-4227(2006).

[17] M. Sieger, F. Balluff, X. Wang, S.-S. Kim, L. Leidner, G. Gauglitz, B. Mizaikoff. On-chip integrated mid-infrared GaAs/AlGaAs Mach-Zehnder interferometer. Anal. Chem., 85, 3050-3052(2013).

[18] X. Wang, S.-S. Kim, R. Roßbach, M. Jetter, P. Michler, B. Mizaikoff. Ultra-sensitive mid-infrared evanescent field sensors combining thin-film strip waveguides with quantum cascade lasers. Analyst, 137, 2322-2327(2012).

[19] P. T. Lin, H. Jung, L. C. Kimerling, A. Agarwal, H. X. Tang. Low-loss aluminium nitride thin film for mid-infrared microphotonics. Laser Photon. Rev., 8, L23-L28(2014).

[20] X. Wang, J. Antoszewski, G. Putrino, W. Lei, L. Faraone, B. Mizaikoff. Mercury-cadmium–telluride waveguides-a novel strategy for on-chip mid-infrared sensors. Anal. Chem., 85, 10648-10652(2013).

[21] J. Cardenas, M. Yu, Y. Okawachi, C. B. Poitras, R. K. Lau, A. Dutt, A. L. Gaeta, M. Lipson. Optical nonlinearities in high-confinement silicon carbide waveguides. Opt. Lett., 40, 4138-4141(2015).

[22] Y. C. Chang, V. Paeder, L. Hvozdara, J. M. Hartmann, H. P. Herzig. Low-loss germanium strip waveguides on silicon for the mid-infrared. Opt. Lett., 37, 2883-2885(2012).

[23] A. Malik, M. Muneeb, S. Pathak, Y. Shimura, J. Van Campenhout, R. Loo, G. Roelkens. Germanium-on-silicon mid-infrared arrayed waveguide grating multiplexers. IEEE Photon. Technol. Lett., 25, 1805-1808(2013).

[24] A. Malik, M. Muneeb, Y. Shimura, J. Van Campenhout, R. Loo, G. Roelkens. Germanium-on-silicon planar concave grating wavelength (de) multiplexers in the mid-infrared. Appl. Phys. Lett., 103, 161119(2013).

[25] A. Malik, M. Muneeb, Y. Shimura, J. Van Campenhout, G. Roelkens. Germanium-on-silicon mid-infrared waveguides and Mach-Zehnder interferometers. IEEE Photonics Conference(2013).

[26] J. Kang, M. Takenaka, S. Takagi. Novel Ge waveguide platform on Ge-on-insulator wafer for mid-infrared photonic integrated circuits. Opt. Express, 24, 11855-11864(2016).

[27] G. Mashanovich, C. Mitchell, J. Soler Penades, A. Khokhar, C. Littlejohns, W. Cao, Z. Qu, S. Stankovic, F. Gardes, T. B. Masaud. Germanium mid-infrared photonic devices. J. Lightwave Technol., 35, 624-630(2017).

[28] U. Younis, S. K. Vanga, A. E.-J. Lim, P. G.-Q. Lo, A. A. Bettiol, K.-W. Ang. Germanium-on-SOI waveguides for mid-infrared wavelengths. Opt. Express, 24, 11987-11993(2016).

[29] A. Bogris, A. Kapsalis, K. Hammani, M. A. Ettabib, M. Brun, P. Labeye, S. Nicoletti, P. Petropoulos, D. Syvridis. Silicon germanium platform enabling mid-infrared to near-infrared conversion for telecom and sensing applications. European Conference on Optical Communication (ECOC)(2014).

[30] M. Brun, P. Labeye, G. Grand, J.-M. Hartmann, F. Boulila, M. Carras, S. Nicoletti. Low loss SiGe graded index waveguides for mid-IR applications. Opt. Express, 22, 508-518(2014).

[31] L. Carletti, P. Ma, B. Luther-Davies, D. D. Hudson, C. Monat, S. Madden, D. J. Moss, M. Brun, S. Ortiz, S. Nicoletti. Nonlinear optical properties of SiGe waveguides in the mid-infrared. CLEO: Science and Innovations, SW3M.7(2014).

[32] L. Carletti, D. Allioux, P. Ma, Y. Yu, B. Luther-Davies, S. Madden, D. Hudson, M. Sinobad, D. Moss, M. Brun. Mid-infrared nonlinear optics in SiGe waveguides. Summer Topical Meeting Series (SUM), 59-60(2015).

[33] R. Soref. Mid-infrared photonics in silicon and germanium. Nat. Photonics, 4, 495-497(2010).

[34] J. Chiles, S. Khan, J. Ma, S. Fathpour. High-contrast, all-silicon waveguiding platform for ultra-broadband mid-infrared photonics. Appl. Phys. Lett., 103, 151106(2013).

[35] J. Soler Penades, C. Alonso-Ramos, A. Khokhar, M. Nedeljkovic, L. Boodhoo, A. Ortega-Moñux, I. Molina-Fernández, P. Cheben, G. Mashanovich. Suspended SOI waveguide with sub-wavelength grating cladding for mid-infrared. Opt. Lett., 39, 5661-5664(2014).

[36] M. Nedeljkovic, S. Stankovic, C. J. Mitchell, A. Z. Khokhar, S. A. Reynolds, D. J. Thomson, F. Y. Gardes, C. G. Littlejohns, G. T. Reed, G. Z. Mashanovich. Mid-infrared thermo-optic modulators in SoI. IEEE Photon. Technol. Lett., 26, 1352-1355(2014).

[37] M. A. Van Camp, S. Assefa, D. M. Gill, T. Barwicz, S. M. Shank, P. M. Rice, T. Topuria, W. M. Green. Demonstration of electrooptic modulation at 2165  nm using a silicon Mach-Zehnder interferometer. Opt. Express, 20, 28009-28016(2012).

[38] J. J. Ackert, D. J. Thomson, L. Shen, A. C. Peacock, P. E. Jessop, G. T. Reed, G. Z. Mashanovich, A. P. Knights. High-speed detection at two micrometres with monolithic silicon photodiodes. Nat. Photonics, 9, 393-396(2015).

[39] M. Muneeb, X. Chen, P. Verheyen, G. Lepage, S. Pathak, E. Ryckeboer, A. Malik, B. Kuyken, M. Nedeljkovic, J. Van Campenhout. Demonstration of silicon-on-insulator mid-infrared spectrometers operating at 3.8  μm. Opt. Express, 21, 11659-11669(2013).

[40] E. Ryckeboer, A. Gassenq, M. Muneeb, N. Hattasan, S. Pathak, L. Cerutti, J. B. Rodriguez, E. Tournié, W. Bogaerts, R. Baets, G. Roelkens. Silicon-on-insulator spectrometers with integrated GaInAsSb photodiodes for wide-band spectroscopy from 1510 to 2300  nm. Opt. Express, 21, 6101-6108(2013).

[41] M. Nedeljkovic, A. V. Velasco, A. Z. Khokhar, A. Delâge, P. Cheben, G. Z. Mashanovich. Mid-infrared silicon-on-insulator Fourier-transform spectrometer chip. IEEE Photon. Technol. Lett., 28, 528-531(2016).

[42] S. Zlatanovic, J. S. Park, S. Moro, J. M. C. Boggio, I. B. Divliansky, A. Nikola, S. Mookherjea, S. Radic. Mid-infrared wavelength conversion in silicon waveguides using ultracompact telecom-band-derived pump source. Nat. Photonics, 4, 561-564(2010).

[43] A. G. Griffith, R. K. Lau, J. Cardenas, Y. Okawachi, A. Mohanty, R. Fain, Y. H. D. Lee, M. Yu, C. T. Phare, C. B. Poitras. Silicon-chip mid-infrared frequency comb generation. Nat. Commun., 6, 6299(2015).

[44] X. Liu, B. Kuyken, G. Roelkens, R. Baets, R. M. Osgood, W. M. J. Green. Bridging the mid-infrared-to-telecom gap with silicon nanophotonic spectral translation. Nat. Photonics, 6, 667-671(2012).

[45] B. Kuyken, X. Liu, R. M. Osgood, R. Baets, G. Roelkens, W. M. J. Green. Mid-infrared to telecom-band supercontinuum generation in highly nonlinear silicon-on-insulator wire waveguides. Opt. Express, 19, 20172-20181(2011).

[46] X. Liu, R. M. Osgood, Y. A. Vlasov, W. M. J. Green. Mid-infrared optical parametric amplifier using silicon nanophotonic waveguides. Nat. Photonics, 4, 557-560(2010).

[47] J. Huang, H. Han, A. Liu, H. Wang, X. Liu, Y. Zou, M.-H. Lu, Y.-F. Chen. Efficient second harmonic generation by mode phase matching in a silicon waveguide. IEEE Photon. J., 9, 6100807(2017).

[48] E. Timurdogan, C. V. Poulton, M. Byrd, M. Watts. Electric field-induced second-order nonlinear optical effects in silicon waveguides. Nat. Photonics, 11, 200-206(2017).

[49] R. K. W. Lau, M. R. E. Lamont, A. G. Griffith, Y. Okawachi, M. Lipson, A. L. Gaeta. Octave-spanning mid-infrared supercontinuum generation in silicon nanowaveguides. Opt. Lett., 39, 4518-4521(2014).

[50] A. G. Griffith, M. Yu, Y. Okawachi, J. Cardenas, A. Mohanty, A. L. Gaeta, M. Lipson. Coherent mid-infrared frequency combs in silicon-microresonators in the presence of Raman effects. Opt. Express, 24, 13044-13050(2016).

[51] M. Yu, Y. Okawachi, A. G. Griffith, M. Lipson, A. L. Gaeta. Mode-locked mid-infrared frequency combs in a silicon microresonator. Optica, 3, 854-860(2016).

[52] R. Shankar, M. Lončar. Silicon photonic devices for mid-infrared applications. Nanophotonics, 3, 329-341(2014).

[53] V. Singh, P. T. Lin, N. Patel, H. Lin, L. Li, Y. Zou, F. Deng, C. Ni, J. Hu, J. Giammarco. Mid-infrared materials and devices on a Si platform for optical sensing. Sci. Technol. Adv. Mater., 15, 014603(2014).

[54] G. Z. Mashanovich, F. Y. Gardes, D. J. Thomson, Y. Hu, K. Li, M. Nedeljkovic, J. Soler Penades, A. Z. Khokhar, C. J. Mitchell, S. Stankovic. Silicon photonic waveguides and devices for near-and mid-IR applications. IEEE J. Sel. Top. Quantum Electron., 21, 407-418(2015).

[55] M. Nedeljkovic, A. Khokhar, Y. Hu, X. Chen, J. Soler Penades, S. Stankovic, H. Chong, D. Thomson, F. Gardes, G. Reed. Silicon photonic devices and platforms for the mid-infrared. Opt. Mater. Express, 3, 1205-1214(2013).

[56] G. Roelkens, U. Dave, A. Gassenq, N. Hattasan, C. Hu, B. Kuyken, F. Leo, A. Malik, M. Muneeb, E. Ryckeboer, S. Uvin, Z. Hens, R. Baets, Y. Shimura, F. Gencarelli, B. Vincent, R. Loo, J. Van Campenhout, L. Cerutti, J.-B. Rodriguez, E. Tournié, X. Chen, M. Nedeljkovic, G. Mashanovich, L. Shen, N. Healy, A. C. Peacock, X. Liu, R. Osgood, W. Green. Silicon-based heterogeneous photonic integrated circuits for the mid-infrared. Opt. Mater. Express, 3, 1523-1536(2013).

[57] N. Hattasan, B. Kuyken, F. Leo, E. M. P. Ryckeboer, D. Vermeulen, G. Roelkens. High-efficiency SOI fiber-to-chip grating couplers and low-loss waveguides for the short-wave infrared. IEEE Photon. Technol. Lett., 24, 1536-1538(2012).

[58] F. Leo, B. Kuyken, N. Hattasan, R. Baets, G. Roelkens. Passive SOI devices for the short-wave-infrared. 16th European Conference on Integrated Optics (ECIO)(2012).

[59] M. S. Rouifed, C. G. Littlejohns, G. X. Tina, H. Qiu, J. Soler Penades, M. Nedeljkovic, Z. Zhang, C. Liu, D. J. Thomson, G. Z. Mashanovich, G. T. Reed, H. Wang. Ultra-compact MMI-based beam splitter demultiplexer for the NIR/MIR wavelengths of 1.55  μm and 2  μm. Opt. Express, 25, 10893-10900(2017).

[60] G. Z. Mashanovich, M. M. Milošević, M. Nedeljkovic, N. Owens, B. Xiong, E. J. Teo, Y. Hu. Low loss silicon waveguides for the mid-infrared. Opt. Express, 19, 7112-7119(2011).

[61] M. M. Milosevic, M. Nedeljkovic, T. M. B. Masaud, E. Jaberansary, H. M. H. Chong, N. G. Emerson, G. T. Reed, G. Z. Mashanovich. Silicon waveguides and devices for the mid-infrared. Appl. Phys. Lett., 101, 121105(2012).

[62] J. Soler Penades, A. Z. Khokhar, M. Nedeljkovic, G. Z. Mashanovich. Low loss mid-infrared SOI slot waveguides. IEEE Photon. Technol. Lett., 27, 1197-1199(2015).

[63] B. Dong, X. Guo, C. P. Ho, B. Li, H. Wang, C. Lee, X. Luo, G.-Q. Lo. Silicon-on-insulator waveguide devices for broadband mid-infrared photonics. IEEE Photon. J., 9, 4501410(2017).

[64] P. T. Lin, S. W. Kwok, H.-Y. G. Lin, V. Singh, L. C. Kimerling, G. M. Whitesides, A. Agarwal. Mid-infrared spectrometer using opto-nanofluidic slot-waveguide for label-free on-chip chemical sensing. Nano Lett., 14, 231-238(2013).

[65] Y. Wei, G. Li, Y. Hao, Y. Li, J. Yang, M. Wang, X. Jiang. Long-wave infrared 1 × 2 MMI based on air-gap beneath silicon rib waveguides. Opt. Express, 19, 15803-15809(2011).

[66] M. Florjańczyk, P. Cheben, S. Janz, A. Scott, B. Solheim, D.-X. Xu. Multiaperture planar waveguide spectrometer formed by arrayed Mach-Zehnder interferometers. Opt. Express, 15, 18176-18189(2007).

[67] B. Troia, A. Z. Khokhar, M. Nedeljkovic, J. Soler Penades, V. M. Passaro, G. Z. Mashanovich. Cascade-coupled racetrack resonators based on the Vernier effect in the mid-infrared. Opt. Express, 22, 23990-24003(2014).

[68] Y. Hu, T. Li, D. J. Thomson, X. Chen, J. Soler Penades, A. Z. Khokhar, C. J. Mitchell, G. T. Reed, G. Z. Mashanovich. Mid-infrared wavelength division (de)multiplexer using an interleaved angled multimode interferometer on the silicon-on-insulator platform. Opt. Lett., 39, 1406-1409(2014).

[69] R. Wang, S. Sprengel, G. Boehm, R. Baets, M.-C. Amann, G. Roelkens. Broad wavelength coverage 2.3  μm III-V-on-silicon DFB laser array. Optica, 4, 972-975(2017).

[70] P. Dong, T.-C. Hu, L. Zhang, M. Dinu, R. Kopf, A. Tate, L. Buhl, D. Neilson, X. Luo, T.-Y. Liow. 1.9  μm hybrid silicon/III-V semiconductor laser. Electron. Lett., 49, 664-666(2013).

[71] G. Roelkens, U. D. Dave, A. Gassenq, N. Hattasan, C. Hu, B. Kuyken, F. Leo, A. Malik, M. Muneeb, E. Ryckeboer, D. Sanchez, S. Uvin, R. Wang, Z. Hens, R. Baets, Y. Shimura, F. Gencarelli, B. Vincent, R. Loo, J. V. Campenhout, L. Cerutti, J. B. Rodriguez, E. Tournié, X. Chen, M. Nedeljkovic, G. Mashanovich, L. Shen, N. Healy, A. C. Peacock, X. Liu, R. Osgood, W. M. J. Green. Silicon-based photonic integration beyond the telecommunication wavelength range. IEEE J. Sel. Top. Quantum Electron., 20, 394-404(2014).

[72] A. Spott, M. Davenport, J. Peters, J. Bovington, M. J. R. Heck, E. J. Stanton, I. Vurgaftman, J. Meyer, J. Bowers. Heterogeneously integrated 2.0  μm CW hybrid silicon lasers at room temperature. Opt. Lett., 40, 1480-1483(2015).

[73] R. Wang, S. Sprengel, G. Boehm, M. Muneeb, R. Baets, M.-C. Amann, G. Roelkens. 2.3  μm range InP-based type-II quantum well Fabry-Perot lasers heterogeneously integrated on a silicon photonic integrated circuit. Opt. Express, 24, 21081-21089(2016).

[74] R. Wang, S. Sprengel, A. Malik, A. Vasiliev, G. Boehm, R. Baets, M.-C. Amann, G. Roelkens. Heterogeneously integrated III-V-on-silicon 2.3x μm distributed feedback lasers based on a type-II active region. Appl. Phys. Lett., 109, 221111(2016).

[75] M. Muneeb, A. Ruocco, A. Malik, S. Pathak, E. Ryckeboer, D. Sanchez, L. Cerutti, J. B. Rodriguez, E. Tournié, W. Bogaerts, M. K. Smit, G. Roelkens. Silicon-on-insulator shortwave infrared wavelength meter with integrated photodiodes for on-chip laser monitoring. Opt. Express, 22, 27300-27308(2014).

[76] R. Wang, S. Sprengel, M. Muneeb, G. Boehm, R. Baets, M.-C. Amann, G. Roelkens. 2  μm wavelength range InP-based type-II quantum well photodiodes heterogeneously integrated on silicon photonic integrated circuits. Opt. Express, 23, 26834-26841(2015).

[77] Z. Cheng, X. Chen, C. Wong, K. Xu, C. K. Fung, Y. Chen, H. K. Tsang. Focusing subwavelength grating coupler for mid-infrared suspended membrane waveguide. Opt. Lett., 37, 1217-1219(2012).

[78] Z. Cheng, X. Chen, C. Y. Wong, K. Xu, H. Tsang. Mid-infrared suspended membrane waveguide and ring resonator on silicon-on-insulator. IEEE Photon. J., 4, 1510-1519(2012).

[79] Y. A. Vlasov, M. O’Boyle, H. F. Hamann, S. J. McNab. Active control of slow light on a chip with photonic crystal waveguides. Nature, 438, 65-69(2005).

[80] Y. Akahane, T. Asano, B. S. Song, S. Noda. High-Q photonic nanocavity in a two-dimensional photonic crystal. Nature, 425, 944-947(2003).

[81] A. Vasiliev, A. Malik, M. Muneeb, B. Kuyken, R. Baets, G. N. Roelkens. On-chip mid-infrared photothermal spectroscopy using suspended silicon-on-insulator microring resonators. ACS Sens., 1, 1301-1307(2016).

[82] X. Wang, Z. Cheng, K. Xu, H. K. Tsang, J.-B. Xu. High-responsivity graphene/silicon-heterostructure waveguide photodetectors. Nat. Photonics, 7, 888-891(2013).

[83] Y. Xia, C. Qiu, X. Zhang, W. Gao, J. Shu, Q. Xu. Suspended Si ring resonator for mid-IR application. Opt. Lett., 38, 1122-1124(2013).

[84] S. Miller, A. Griffith, M. Yu, A. L. Gaeta, M. Lipson. Low-loss air-clad suspended silicon platform for mid-infrared photonics. CLEO: Science and Innovations, STu3Q.6(2016).

[85] E. Yablonovitch. Inhibited spontaneous emission in solid-state physics and electronics. Phys. Rev. Lett., 58, 2059-2062(1987).

[86] S. John. Strong localization of photons in certain disordered dielectric superlattices. Phys. Rev. Lett., 58, 2486-2489(1987).

[87] R. Shankar, I. Bulu, R. Leijssen, M. Lončar. Study of thermally-induced optical bistability and the role of surface treatments in Si-based mid-infrared photonic crystal cavities. Opt. Express, 19, 24828-24837(2011).

[88] R. Shankar, R. Leijssen, I. Bulu, M. Lončar. Mid-infrared photonic crystal cavities in silicon. Opt. Express, 19, 5579-5586(2011).

[89] C. Reimer, M. Nedeljkovic, D. J. Stothard, M. O. Esnault, C. Reardon, L. O’Faolain, M. Dunn, G. Z. Mashanovich, T. F. Krauss. Mid-infrared photonic crystal waveguides in silicon. Opt. Express, 20, 29361-29368(2012).

[90] P. Cheben, P. J. Bock, J. H. Schmid, J. Lapointe, S. Janz, D.-X. Xu, A. Densmore, A. Delâge, B. Lamontagne, T. J. Hall. Refractive index engineering with subwavelength gratings for efficient microphotonic couplers and planar waveguide multiplexers. Opt. Lett., 35, 2526-2528(2010).

[91] J. Schmid, P. Cheben, P. Bock, R. Halir, J. Lapointe, S. Janz, A. Dela, A. Densmore, J.-M. Fedeli, T. Hall. Refractive index engineering with subwavelength gratings in silicon microphotonic waveguides. IEEE Photon. J., 3, 597-607(2011).

[92] X. Chen, K. Xu, Z. Cheng, C. K. Y. Fung, H. K. Tsang. Wideband subwavelength gratings for coupling between silicon-on-insulator waveguides and optical fibers. Opt. Lett., 37, 3483-3485(2012).

[93] X. Xu, H. Subbaraman, J. Covey, D. Kwong, A. Hosseini, R. T. Chen. Complementary metal–oxide–semiconductor compatible high efficiency subwavelength grating couplers for silicon integrated photonics. Appl. Phys. Lett., 101, 031109(2012).

[94] J. Gonzalo Wangüemert-Pérez, P. Cheben, A. Ortega-Moñux, C. Alonso-Ramos, D. Pérez-Galacho, R. Halir, I. Molina-Fernández, D.-X. Xu, J. H. Schmid. Evanescent field waveguide sensing with subwavelength grating structures in silicon-on-insulator. Opt. Lett., 39, 4442-4445(2014).

[95] R. Halir, A. Ortega-Monux, J. H. Schmid, C. Alonso-Ramos, J. Lapointe, D.-X. Xu, J. G. Wanguemert-Perez, I. Molina-Fernandez, S. Janz. Recent advances in silicon waveguide devices using sub-wavelength gratings. IEEE J. Sel. Top. Quantum Electron., 20, 279-291(2014).

[96] J. Wang, I. Glesk, L. R. Chen. Subwavelength grating filtering devices. Opt. Express, 22, 15335-15345(2014).

[97] J. Soler Penades, A. Ortega-Moñux, M. Nedeljkovic, J. G. Wangüemert-Pérez, R. Halir, A. Z. Khokhar, C. Alonso-Ramos, Z. Qu, I. Molina-Fernández, P. Cheben, G. Z. Mashanovich. Suspended silicon mid-infrared waveguide devices with subwavelength grating metamaterial cladding. Opt. Express, 24, 22908-22916(2016).

[98] R. A. Johnson, P. R. D. L. Houssaye, C. E. Chang, C. Pin-Fan, M. E. Wood, G. A. Garcia, I. Lagnado, P. M. Asbeck. Advanced thin-film silicon-on-sapphire technology: microwave circuit applications. IEEE Trans. Electron. Devices, 45, 1047-1054(1998).

[99] G. Imthurn. The history of silicon-on-sapphire(2007).

[100] T. Baehr-Jones, A. Spott, R. Ilic, B. Penkov, W. Asher, M. Hochberg. Silicon-on-sapphire integrated waveguides for the mid-infrared. Opt. Express, 18, 12127-12135(2010).

[101] F. Li, S. D. Jackson, C. Grillet, E. Magi, D. Hudson, S. J. Madden, Y. Moghe, C. O’Brien, A. Read, S. G. Duvall. Low propagation loss silicon-on-sapphire waveguides for the mid-infrared. Opt. Express, 19, 15212-15220(2011).

[102] N. Singh, D. D. Hudson, Y. Yu, C. Grillet, S. D. Jackson, A. Casas-Bedoya, A. Read, P. Atanackovic, S. G. Duvall, S. Palomba. Midinfrared supercontinuum generation from 2 to 6  μm in a silicon nanowire. Optica, 2, 797-802(2015).

[103] Y. Zou, H. Subbaraman, S. Chakravarty, X. Xu, A. Hosseini, W.-C. Lai, P. Wray, R. T. Chen. Grating-coupled silicon-on-sapphire integrated slot waveguides operating at mid-infrared wavelengths. Opt. Lett., 39, 3070-3073(2014).

[104] Y. Zou, S. Chakravarty, R. T. Chen. Mid-infrared silicon-on-sapphire waveguide coupled photonic crystal microcavities. Appl. Phys. Lett., 107, 081109(2015).

[105] A. Spott, Y. Liu, T. Baehr-Jones, R. Ilic, M. Hochberg. Silicon waveguides and ring resonators at 5.5  mu m. Appl. Phys. Lett., 97, 213501(2010).

[106] R. Shankar, I. Bulu, M. Loncar. Integrated high-quality factor silicon-on-sapphire ring resonators for the mid-infrared. Appl. Phys. Lett., 102, 051108(2013).

[107] Z. Cheng, X. Chen, C. Wong, K. Xu, C. K. Fung, Y. Chen, H. K. Tsang. Mid-infrared grating couplers for silicon-on-sapphire waveguides. IEEE Photon. J., 4, 104-113(2012).

[108]

[109] Y. Zou, S. Chakravarty, D. N. Kwong, W.-C. Lai, X. Xu, X. Lin, A. Hosseini, R. T. Chen. Cavity-waveguide coupling engineered high sensitivity silicon photonic crystal microcavity biosensors with high yield. IEEE J. Sel. Top. Quantum Electron., 20, 171-180(2014).

[110] C. Y. Wong, Z. Cheng, X. Chen, K. Xu, C. K. Fung, Y. M. Chen, H. K. Tsang. Characterization of mid-infrared silicon-on-sapphire microring resonators with thermal tuning. IEEE Photon. J., 4, 1095-1102(2012).

[111] W.-C. Lai, S. Chakravarty, Y. Zou, R. T. Chen. Multiplexed detection of xylene and trichloroethylene in water by photonic crystal absorption spectroscopy. Opt. Lett., 38, 3799-3802(2013).

[112] Y. Zou, S. Chakravarty, P. Wray, R. T. Chen. Experimental demonstration of propagation characteristics of mid-infrared photonic crystal waveguides in silicon-on-sapphire. Opt. Express, 23, 6965-6975(2015).

[113] Y. Zou, S. Chakravarty, L. Zhu, R. T. Chen. The role of group index engineering in series-connected photonic crystal microcavities for high density sensor microarrays. Appl. Phys. Lett., 104, 141103(2014).

[114] S. Chakravarty, Y. Zou, W.-C. Lai, R. T. Chen. Slow light engineering for high Q high sensitivity photonic crystal microcavity biosensors in silicon. Biosens. Bioelectron., 38, 170-176(2012).

[115] Y. Zou, S. Chakravarty, P. Wray, R. T. Chen. Mid-infrared holey and slotted photonic crystal waveguides in silicon-on-sapphire for chemical warfare simulant detection. Sens. Actuators B, 221, 1094-1103(2015).

[116] W.-C. Lai, S. Chakravarty, Y. Zou, R. T. Chen. Silicon nano-membrane based photonic crystal microcavities for high sensitivity bio-sensing. Opt. Lett., 37, 1208-1210(2012).

[117] Y. Zou, S. Chakravarty, W.-C. Lai, C.-Y. Lin, R. T. Chen. Methods to array photonic crystal microcavities for high throughput high sensitivity biosensing on a silicon-chip based platform. Lab Chip, 12, 2309-2312(2012).

[118] C. J. Smith, R. Shankar, M. Laderer, M. B. Frish, M. Loncar, M. G. Allen. Sensing nitrous oxide with QCL-coupled silicon-on-sapphire ring resonators. Opt. Express, 23, 5491-5499(2015).

[119] N. Singh, A. Casas-Bedoya, D. D. Hudson, A. Read, E. Mägi, B. J. Eggleton. Mid-IR absorption sensing of heavy water using a silicon-on-sapphire waveguide. Opt. Lett., 41, 5776-5779(2016).

[120] G. M. Hale, M. R. Querry. Optical constants of water in the 200-nm to 200-μm wavelength region. Appl. Opt., 12, 555-563(1973).

[121] Y. Zou, S. Chakravarty, C.-J. Chung, R. T. Chen. Miniature mid-infrared thermooptic switch with photonic crystal waveguide based silicon-on-sapphire Mach-Zehnder interferometers. Proc. SPIE, 9753, 97530Q(2016).

[122] M. Soljačić, J. D. Joannopoulos. Enhancement of nonlinear effects using photonic crystals. Nat. Mater., 3, 211-219(2004).

[123] N. Singh, D. D. Hudson, B. J. Eggleton. Silicon-on-sapphire pillar waveguides for mid-IR supercontinuum generation. Opt. Express, 23, 17345-17354(2015).

[124] Y. Huang, E. Tien, S. Gao, S. Kalyoncu, Q. Song, F. Qian, E. Adas, D. Yildirim, O. Boyraz. Electrical signal-to-noise ratio improvement in indirect detection of mid-IR signals by wavelength conversion in silicon-on-sapphire waveguides. Appl. Phys. Lett., 99, 181122(2011).

[125] W. Zhaolu, L. Hongjun, H. Nan, S. Qibing, L. Xuefeng. Mid-infrared Raman amplification and wavelength conversion in dispersion engineered silicon-on-sapphire waveguides. J. Opt., 16, 015206(2014).

[126] Z. Wang, H. Liu, N. Huang, Q. Sun, J. Wen, X. Li. Influence of three-photon absorption on mid-infrared cross-phase modulation in silicon-on-sapphire waveguides. Opt. Express, 21, 1840-1848(2013).

[127] C.-M. Chang, O. Solgaard. Fano resonances in integrated silicon Bragg reflectors for sensing applications. Opt. Express, 21, 27209-27218(2013).

[128] G. Tittelbach, B. Richter, W. Karthe. Comparison of three transmission methods for integrated optical waveguide propagation loss measurement. J. Opt. Pure Appl. Opt., 2, 683-700(1993).

[129] J. Chiles, S. Fathpour. Single-mode and single-polarization photonics with anchored-membrane waveguides. Opt. Express, 24, 19337-19343(2016).

[130] C. M. Chang, O. Solgaard. Monolithic silicon waveguides in standard silicon. IEEE Micro, 33, 32-40(2013).

[131] P. T. Lin, V. Singh, Y. Cai, L. C. Kimerling, A. Agarwal. Air-clad silicon pedestal structures for broadband mid-infrared microphotonics. Opt. Lett., 38, 1031-1033(2013).

[132] P. T. Lin, V. Singh, J. Hu, K. Richardson, J. D. Musgraves, I. Luzinov, J. Hensley, L. C. Kimerling, A. Agarwal. Chip-scale mid-infrared chemical sensors using air-clad pedestal silicon waveguides. Lab Chip, 13, 2161-2166(2013).

[133] A. S. Richard, J. E. Stephen, R. B. Walter. Silicon waveguided components for the long-wave infrared region. J. Opt. A, 8, 840-848(2006).

[134] Y. Yue, L. Zhang, H. Huang, R. G. Beausoleil, A. E. Willner. Silicon-on-nitride waveguide with ultralow dispersion over an octave-spanning mid-infrared wavelength range. IEEE Photon. J., 4, 126-132(2012).

[135] S. Khan, J. Chiles, J. Ma, S. Fathpour. Silicon-on-nitride waveguides for mid-and near-infrared integrated photonics. Appl. Phys. Lett., 102, 121104(2013).

[136] G. Mashanovich, W. Headley, M. Milosevic, N. Owens, E. Teo, B. Xiong, P. Yang, M. Nedeljkovic, J. Anguita, I. Marko. Waveguides for mid-infrared group IV photonics. 7th IEEE International Conference on Group IV Photonics (GFP), 374-376(2010).

[137] A. Spott, J. Peters, M. L. Davenport, E. J. Stanton, C. D. Merritt, W. W. Bewley, I. Vurgaftman, C. S. Kim, J. R. Meyer, J. Kirch, L. J. Mawst, D. Botez, J. E. Bowers. Quantum cascade laser on silicon. Optica, 3, 545-551(2016).

[138] A. Spott, J. Peters, M. Davenport, E. Stanton, C. Zhang, C. Merritt, W. Bewley, I. Vurgaftman, C. Kim, J. Meyer, J. Kirch, L. Mawst, D. Botez, J. Bowers. Heterogeneously integrated distributed feedback quantum cascade lasers on silicon. Photonics, 3, 35(2016).

[139] B. Kumari, A. Barh, R. K. Varshney, B. P. Pal. Silicon-on-nitride slot waveguide: a promising platform as mid-IR trace gas sensor. Sens. Actuators B, 236, 759-764(2016).

[140] Y. Chen, H. Lin, J. Hu, M. Li. Heterogeneously integrated silicon photonics for the mid-infrared and spectroscopic sensing. ACS Nano, 8, 6955-6961(2014).

[141] J. Chiles, S. Fathpour. Mid-infrared integrated waveguide modulators based on silicon-on-lithium-niobate photonics. Optica, 1, 350-355(2014).

[142] M. Nedeljkovic, R. Soref, G. Z. Mashanovich. Free-carrier electrorefraction and electroabsorption modulation predictions for silicon over the 1-14-μm infrared wavelength range. IEEE Photon. J., 3, 1171-1180(2011).