Uncooled IR sensors with tunable MEMS Fabry-Pérot filters for the long-wave infrared range

In this paper we describe the design, the fabrication and the properties of tunable MEMS Fabry-Pérot (FP) filters for the long-wave infrared range (LWIR). Based on a mid-wave IR (MWIR) device, completely new optical and electro mechanical designs have to be used to extend the spectral range to the LWIR. A new set of optical thin films with low and high refractive index materials and an additional third thin film with medium refractive index are introduced as well. A further approach is focused on covering both, the mid-wave and long wave IR range in one device to obtain dual-band FP filters which is reported too. Significant improvements towards reduced acceleration response were achieved using two spring suspended reflectors.