Title :
Towards MEMS-based long-wavelength infrared tuneable Fabry-Perot filters
Author :
Haifeng Mao ; Martyniuk, Mariusz ; Silva, Dilusha ; Antoszewski, Jarek ; Bumgarner, John ; Faraone, Lorenzo
Author_Institution :
Sch. of Electr., Electron. & Comput. Eng., Univ. of Western Australia, Crawley, WA, Australia
Abstract :
This paper describes the realization of LWIR (8-12 μm) Fabry-Perot filters on basis of our previously demonstrated SWIR (1.6-2.5 μm) or MWIR (3-5 μm) filter technique. An innovative filter design employing a single layer of Ge as the top mirror is proposed and optical modelling shows that the filter can potentially achieve spectral characteristics required by the LWIR spectral imaging applications. As a proof of concept, filters with fixed air cavity were fabricated and bowing in the suspended mirror was corrected by depositing a thin SiNx stress compensation layer underneath the mirror. Transmission measurement was carried out on the filter exhibiting the least bowing, despite some spectral degradation compared to the theoretical model of the filer, showing not optimal but adequate transmission and bandwidth for multispectral imaging applications.
Keywords :
elemental semiconductors; germanium; infrared spectra; micro-optomechanical devices; microfabrication; mirrors; optical design techniques; optical fabrication; optical filters; optical tuning; silicon compounds; Ge-SiNx; LWIR Fabry-Perot filters; LWIR spectral imaging applications; MEMS-based long-wavelength infrared tuneable Fabry-Perot filters; bowing; filter design; fixed air cavity; multispectral imaging applications; optical modelling; single layer; spectral characteristics; suspended mirror; thin stress compensation layer; transmission measurement; wavelength 8 mum to 12 mum; Fabry-Perot; Mirrors; Optical device fabrication; Optical filters; Optical imaging; Optical sensors; Stress; Fabry-Perot filters; Long-wavelength infrared(LWIR); Micro-electromechanical systems (MEMS);
Conference_Titel :
Optoelectronic and Microelectronic Materials & Devices (COMMAD), 2014 Conference on
Conference_Location :
Perth, WA
Print_ISBN :
978-1-4799-6867-1
DOI :
10.1109/COMMAD.2014.7038677
