Investigation of MEMS-based spectrally adaptive Fabry-Pérot interferometers for long-wave infrared applications

Achieving miniaturised tunable spectral filtering in the long-wave infrared (LWIR) region would enhance/create opportunities across a broad range of applications. It is of particular importance to achieve on-chip fully passive thermal imaging with spectral selectivity, allowing remote target recognition since the radiation spectrum of objects at room temperature peaks in the LWIR. This work focuses on microelectromechanical system-based tunable Fabry-Perot filters using Germanium and Barium Fluoride optical thin films for high-performance wavelength discrimination via electrostatic actuation of freely suspended distributed Bragg's reflector supported by Silicon Nitride membrane. It describes the pathways towards the development of fully portable on-chip microspectrometer that is field deployable for applications requiring mechanical robustness, such as robots and unmanned aerial vehicles.