Experimental investigation of laser emission of dye-doped cholesteric liquid crystals with a cholesteric reflector

Dye-doped cholesteric liquid crystal (CLC) behaves like a one-dimensional photonic crystal laser when pumped by a second harmonic Nd-YAG pulsed laser. Usually circularly polarized laser light in the same sense as the cholesteric helix is emitted from both directions of the lasing cell. In this paper, we experimentally demonstrate the laser emission enhancement and investigate the corresponding polarization state from the dye-doped CLC laser in stack with another CLC reflector. Cell gap and dye concentration are important factors affecting the optical efficiency of the CLC lasers.