PA40 High efficiency lasing using cholesteric film with notch reflectance band

Abstract

Cholesteric liquid crystals (ChLCs) are known to self-organize into helical structures with periodicities of a few hundred nanometers and thus have been studied as distributed feedback (DFB) lasers. There is a drawback of low slope efficiency in the conventional ChLC lasers, in which the laser dye is directly doped in the ChLCs and the ChLC cavity is deteriorated due to heat generated by light excitation. In this study, we report an improved slope efficiency in a ChLC laser with a three-layered structure, in which gain medium is eparated from the ChLC cavity.