Electrically tunable Fabry–Perot lasing in nematic liquid crystal cells

Abstract

Liquid crystal lasers have great potential as small-sized, low-cost, widely tunable lasers. In this paper, we report tunable lasing based on Fabry-Perot interference in nematic liquid crystal (NLC) cells with a low quality factor. The influence of the cell thickness on the laser performance is addressed in detail. Cells with and without an aluminum mirror as a back electrode were investigated, and the experimental results were compared with theory and simulations. Applying a small voltage over the NLC cell gave rise to a reorientation of the molecules. This enabled electrical tuning of the emission wavelength over more than 9 nm. Although the lasing threshold is higher than for cholesteric liquid crystal lasers, the Fabry-Perot type liquid crystal laser offers similar slope efficiency. © 2014 Optical Society of America.