Influence of the light induced molecular transformations on the helix pitch and lasing spectra of cholesteric liquid crystals

摘要

A new possible method of frequency tuning of the distributed feedback laser (DFB) based on cholesteric liquid crystals (CLC) is investigated. In this method the active media is irradiated with UV light to stimulate photo-transformation of the molecules of chiral dopant. This transformation changes twisting power of chiral dopant and, as results, the position of the reflection band of CLC. Based on this principle, fluent and reversable frequency tuning of the lasing irradiation of DFB-laser is realized.