Fabry Perot etalon with polymer cholesteric liquid-crystal mirrors

We present what we believe to be the first implementation of a Fabry-Perot (FP) etalon using polymer cholesteric liquid-crystal mirrors. These polymer mirrors have each been fabricated onto a single substrate, which allows the FP cavity spacing to be only a few micrometers wide. For the experimental results presented, cavity lengths of 13.8 and 7.6 microm yield near-infrared free spectral ranges of 24.8 and 45.6 nm, respectively. The measured finesse of 14.31 is approaching the limitation imposed by the reflectivity of the mirrors.