Occurence of active layer optical properties on some Lasing characteristics dye-doped Ch LC

TL;DR

This study investigates how the texture quality and thickness of dye-doped cholesteric liquid crystals affect their lasing properties, revealing stable single-mode lasing in certain textured configurations and the applicability of the coupled wave model.

Contribution

It demonstrates the influence of texture quality and substrate orientation on lasing characteristics and introduces the phase jump mechanism in steroidal CLC lasing spectra.

Findings

Stable single-mode lasing occurs with perpendicular substrate orientation.

Lasing thresholds increase with texture deterioration.

Lasing spectra can be modeled using the coupled wave approach.

Abstract

Effect of a planar texture quality and its thickness on lasing spectrums and thresholds in dye-doped cholesteric liquid crystal (CLC) of steroid type is explored. Transition from the qualitative planar texture to the poor texture quality is accompanied by change of characteristic mode structures and by shift of barycentre in the long-wave side and the considerable growth of the lasing threshold. It is found that in the CLC texture created by substrates with perpendicular directions of orientation the stable single-mode lasing takes place. The nature of oscillated modes in such texture is caused by phase jump. The gained results show that in steroid CLC, unlike induced one, lasing spectrums is possible to feature with the coupled wave model. Key words: steroidal cholesteric liquid crystal, distributed feedback lasing, oscillation thresholds, phase defect of periodical structure, transmission and lasing spectra