Thermal degradation of the distributed-feedback cavity in cholesteric liquid crystal lasers

In this work, cholesteric liquid crystal (CLC) laser emission from two different liquid crystal hosts doped with the same laser dye was studied. For both systems, the lasing thresholds were measured and the energy output was studied at different pump energies and at different temperatures. When the pump energy was increased, a shift of lasing wavelength and a decrease of emission in one sample were observed. We argue that this phenomenon is associated with thermal degradation of the distributed-feedback cavity caused by laser heating and the temperature induced changes of the cholesteric pitch.