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Cunningham, Brian T. Cunningham, Brian T. Bhargava, Rohit Wasserman, Daniel M. Liu, Gang Logan Liu, Jui-Nung 2015-07-22T22:45:59Z 2015-07-22T22:45:59Z 2017-07-23T09:15:35Z 2015-05 2015-04-24 Characteristic molecular vibrational absorption wavelengths in mid-infrared (mid-IR) have been discovered for various applications, and as a result, a faster summary of an MIR spectrum can be gained by probing a set of discrete spectral fingerprints only, enabling many applications including fast early cancer diagnostics, real-time spectroscopic observation, on-chip chemical sensing, and simple/compact mid-IR instrumentation. In this ‘discrete-frequency infrared’ (DF-IR) spectroscopy approach, there is no Fourier transform infrared (FT-IR) interferometer that continuously scans a spectrum, and acquisition of spectral information can be made rapidly by combining an MIR detector and a tunable single-peak narrowband light source, such as selective thermal emitters, quantum cascade (QC) lasers, or a combination of a broadband incandescent globar and filters. This thesis explores the DF-IR approach by using photonic filtering that is based on guided mode resonance (GMR). First, a useful analytical framework for optimal design of GMR devices is established based on a sound understanding of the underlying physics, and can be used to complement numerical electromagnetic simulations. Then, guided by this judicious design, the thesis presents experimental realization of high-performance GMR filters in the C-H stretching region (3-4 µm or 2500-3300 cm-1) of the mid-IR, and demonstrates GMR-filter-based DF-IR microspectroscopy for the first time. Last but not the least, this thesis introduces a new type of high-refractive-index photonic filter in the challenging but important molecular fingerprint mid-IR (6-10 µm or 1000-1600 cm-1) that shows behaviors distinct from conventional GMR. The combination of the high-index photonic devices and the recently developed QC emitters is proposed as a novel, promising solution to high-quality DF-IR microspectroscopy. Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2017-05-01 The student, Jui-Nung Liu, accepted the attached license on 2015-04-22 at 17:57. The student, Jui-Nung Liu, submitted this Dissertation for approval on 2015-04-22 at 18:17. This Dissertation was approved for publication on 2015-04-24 at 08:28. DSpace SAF Submission Ingestion Package generated from Vireo submission #8039 on 2015-07-22 at 14:26:20 Made available in DSpace on 2015-07-22T22:45:59Z (GMT). No. of bitstreams: 2 LIU-DISSERTATION-2015.pdf: 4201423 bytes, checksum: fdcd9760f5fe4f9a5199fee4fba1a3fb (MD5) LICENSE.txt: 4209 bytes, checksum: 4d613f9c6e3537afdc156bfd5b5c5e53 (MD5) Previous issue date: 2015-04-24 Embargo set by: Seth Robbins for item 80017 Lift date: 2017-07-22T22:46:21Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Limited Restriction Lifted for Item 80017 on 2017-07-23T09:15:35Z. application/pdf http://hdl.handle.net/2142/78776 en Copyright 2015 Jui-Nung Liu Photonic crystal Guided resonance Infrared spectroscopy Integrated narrowband guided mode resonance photonic filters for advanced mid-infrared microspectroscopy text text 2015-5 Electrical & Computer Eng Electrical & Computer Engr University of Illinois at Urbana-Champaign Dissertation Ph.D.