A fast MEMS infrared microspectrometer for the measurement of hydrocarbon gases

A new fast infrared microspectrometer based on a MEMS tunable Fabry-Pérot filter (μFPF) is reported. In contrast to previous designs the acquisition time for a complete spectrum is decreased 50 times and the spectral resolution is improved 3 times. This is achieved by the use of higher interference orders and the combination with a room temperature operated PbSe photodetector. Such a system will be especially useful for the measurement of hydrocarbon gases in the spectral range of (3.1∶3.8) µm. The μFPF is tuned sinusoidally over the entire wavelength range in about 100 ms. Methods for offset elimination and drift compensation were developed as well.