Abstract: A new-type tunable infrared filter-liquid crystal Fabry-Perot filter is presented. Its principle, parameter and implementing are introduced. Dependence of transmission spectrum, finesse, and bandwidth on mirror reflectivity and cavity gap are discussed. The impact of applied voltage and temperature on transmission wavelength is analyzed. Several polarization insensitive modules are given. The applications of liquid crystal Fabry-Perot filter to space sensing, especially infrared sensing, are foreseen.

Key words: tunable filter, crystal liquid, Fabry-Perot interferometer, infrared