Transverse Mode Analysis of Gain-Separated Cholesteric Liquid Crystal Laser with In-plane Helix Alignment by FDTD Method

Abstract

Cholesteric liquid crystal (ChLC) waveguide laser with a separated gain layer was analyzed by the Finite Difference Time Domain (FDTD) method. The device consists of a ChLC layer with inplane-helix alignment and a thin active layer placed on one side of the waveguide. Single longitudinal mode lasing was obtained at the selective reflection band edge because of distributed feedback occuring in the ChLC. Furthermore, single transverse mode lasing was obtained when the ChLC layer was 1 µ m thick.