Title :
Large-Area MEMS-Based Distributed Bragg Reflectors for Short-Wave and Mid-Wave Infrared Hyperspectral Imaging Applications
Author :
Tripathi, Dhirendra Kumar ; Haifeng Mao ; Dilusha Silva, K.K.M.B. ; Bumgarner, John W. ; Martyniuk, Mariusz ; Dell, John M. ; Faraone, Lorenzo
Author_Institution :
Sch. of Electr., Electron., & Comput. Eng., Univ. of Western Australia, Perth, WA, Australia
Abstract :
We present the design, fabrication, and optical characterization of silicon-air-silicon-based distributed Bragg reflectors, or quarter wavelength mirrors, in sizes ranging from 200 μm × 200 μm to 5 mm × 5 mm. Such mirrors can be used in conjunction with either single-element photodetectors or large-area focal plane arrays to realize tunable multispectral sensors or adaptive focal plane arrays from the short-wave infrared wavelength ranges (1500-3000 nm) to mid-wave infrared wavelength (3000-6000 nm) ranges. Surface optical profile measurements indicate a flatness of the order of 20-30 nm in the fabricated structures across several millimetres. Single point spectral measurements on devices show excellent agreement with simulated optical models. The fabricated distributed Bragg reflectors show ~94% reflectivity, which is in close agreement with theoretical reflectivity. The demonstrated high reflectivity across a wide wavelength range renders them suitable as broadband reflectors. Finally, we present optical transmittance modeling results for Fabry-Pérot filters based on these distributed Bragg reflectors.
Keywords :
distributed Bragg reflectors; elemental semiconductors; focal planes; hyperspectral imaging; infrared spectra; micromechanical devices; optical filters; optical variables measurement; photodetectors; silicon; Fabry-Perot filters; Si; adaptive focal plane arrays; large-area MEMS; large-area focal plane arrays; mid-wave infrared hyperspectral imaging; mid-wave infrared wavelength; optical transmittance; quarter wavelength mirrors; short-wave infrared hyperspectral imaging; short-wave infrared wavelength; silicon-air-silicon-based distributed Bragg reflectors; single point spectral measurements; single-element photodetectors; surface optical profile measurements; tunable multispectral sensors; wavelength 1500 nm to 3000 nm; wavelength 3000 nm to 6000 nm; Distributed Bragg reflectors; Optical device fabrication; Optical imaging; Optical reflection; Optical refraction; Optical variables control; Silicon; Fabry-P??rot filter; Fabry-P?rot filter; Focal plane array; distributed Bragg reflector; mid-wave infrared; mid-wave infrared.; short-wave infrared;
Journal_Title :
Microelectromechanical Systems, Journal of
DOI :
10.1109/JMEMS.2015.2477853
