Incident angle and polarization effects on the dye-doped cholesteric liquid crystal laser

Polarization effect of the pulsed pumping laser on the lasing characteristics of the dye-doped right-handed cholesteric liquid crystal (CLC) is studied at different incident angles. At a small incident angle (<18°), the CLC laser performance is independent of the polarization state of the pumping laser. As the incident angle exceeds 18°, the CLC laser emission strongly depends on the polarization state of the pumping laser. As the incident angle increases, the lasing efficiency of the CLC laser is dramatically decreased for those excited by the right-handed circularly polarized or linearly polarized laser, but barely affected by the left-handed circularly polarized laser. As the incident angle exceeds ∼31°, lasing phenomenon diminishes under the excitation of the right-handed circularly polarized laser. The lasing threshold pumped by the linearly polarized laser is ∼2× higher than that pumped by the left-handed circularly polarized laser.