Dual-band MEMS Fabry-Pérot filter with two movable reflectors for mid- and long-wave infrared microspectrometers

A tunable dual-band MEMS Fabry-Pérot filter for simultaneous use of the spectral ranges from 8 μm to 10.5 μm and from 4 μm to 5 μm is reported. A peak transmittance of at least 75% and a FWHM of less than 200 nm were measured. The maximum control voltage is 41 V. Two movable reflector carriers compensate the influence of gravitational force on the central wavelength. The device can withstand mechanical shocks according to Mil-Std-883G, method 2002.4, test condition B. The filter is integrated in a tiny, robust and fast microspectrometer module with the size of a TO-8 housing.