High-performance mid-infrared filter arrays for gas sensing

We have developed a static Fabry Perot based filter array operating in the mid-infrared range from ~2 to 4.5 μm, matching the absorption region of several volatile organic compounds. Each filter consists of a cavity system formed by two distributed bragg reflectors with a tuning element with varying length in between. The filters with high transmission (>80%) and controllable transmission peak width are integrated with an array of pyroelectric detectors. The robustness, easy-fabrication and the possibility to tune the optical response to a specific application make the integrated filter arrays suitable for compact sensing systems.