PA21 Consideration on Lasing Condition of Cholesteric Liquid Crystal Doped with Polymeric Dye

Abstract

Cholesteric liquid crystals (CLC) are 1-D photonic bandgap materials due to their natural periodic structure. The bandgap structure of the CLC can allow lots of photonic phenomenon, i. e. mirrorless lasing. In this study, we report a tunable mirrorless lasing from a dye-doped CLC cell. It has high emission efficiency and low threshold energy. Our lasing always appears at the low energy edge of the photonic bandgap, but not at the high energy edge. From the result of depolarized FT-IR and depolarized fluorescence measurements, we concluded that this selection was determined by the molecular orientation.