面内螺旋配向コレステリック液晶のレーザー発振特性

抄録

We describe a cholesteric liquid crystal (ChLC) laser with an in-plane helix alignment where the ChLC helix lies in the in-plane direction of the cell and report an improvement in the threshold characteristics. The in-plane helix alignment of ChLCs was formed by applying an in-plane electric field in a cell with homeotropic surface treatment while cooling the sample from the isotropic phase. The energy threshold was 0.3 mJ/cm², which was found to be less than 1/10 of conventional planarly-aligned ChLC lasers. The threshold gain was measured using variable stripe length method and was determined as 1 cm^-1, which is approximately 1/100 of conventional planar devices with a cell-gap of 10 μm. The improvement of the energy threshold is attributed to small threshold gain attained in these devices.