Periodic Filters with a Three-Mirror Gire-Tournois Resonator in a Michelson Interferometer

A periodic optical filter based on a Michelson interferometer with a three-mirror Gire-Tournois resonator in one of the two arms is analyzed. We derive the general condition for the occurrence of flattop spectra. The results show that flattop spectra can be obtained by suitably choosing the reflective coefficients of individual mirrors