Effect of crosslinking on the photonic bandgap in deformable cholesteric elastomers

Cholesteric liquid crystal (CLC) application for tunable lasing devices has become a subject of study for many research groups. In particular, embedding the liquid crystal in an elastomer allows tunability by simple mechanical stretching. Here we report a study on the dependence of the selective reflection band on the stretching together with measurements of film relaxation after stretching, and we try to discuss and elucidate the role of crosslinking in the polymer matrix. We obtained laser devices made with cholesteric liquid crystal elastomers in a three-layer configuration, where an isotropic layer containing a laser dye is sandwiched between two CLC elastomers: in this work we show some preliminary but quantitative results on laser tunability.