# The Effect of Defect Layer on Lasing in Cholesteric Liquid Crystal

## TL;DR

This paper analyzes how a defect layer in cholesteric liquid crystals affects the photonic density of states and light behavior, revealing potential applications in low-threshold lasers and optical devices.

## Contribution

It provides a detailed calculation of the photonic density of states in defected cholesteric liquid crystals and explores their potential for laser and optical device applications.

## Key findings

- Maximum PDS occurs when the defect is at the system's center.
- The system can function as a low-threshold laser and optical filter.
- PDS depends on absorption and gain parameters.

## Abstract

The photonic density of states (PDS) of eigen polarizations (EPs) in cholesteric liquid crystal (CLC) cells with a defect layer inside are calculated. The dependences for the PDS and light intensity in the defect layer on the parameters characterizing absorption and gain are obtained. We investigated the possibility of connections between the PDS and the density of the light energy accumulated in the system. The influence of the defect layer and CLC layer on the PDS are investigated. It is shown that the PDS is maximum when the defect is in the centre of the system. We showed also that the subject system can work as a low threshold laser, a multiposition trigger, filter, etc.

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Source: https://tomesphere.com/paper/1705.02061