Oblique-incidence liquid-crystal-tunable étalon

The experimental properties and a detailed model of a nematic liquid-crystal-tunable Fabry-Perot étalon with obliquely incident light are reported. As a single-wavelength switch, the étalon has an extinction ratio of 20.3 dB, an insertion loss of -1.7 dB, and a millisecond switching speed. As a filter, the étalon has a finesse of 15.1, a free spectral range of 20.4 nm, and a continuous tuning range of over 40 nm with less than 5 V.