Polarization and polarization control of random lasers from dye-doped nematic liquid crystals.

A polarimetric study of random laser (RL) emitted from dye-doped nematic liquid crystals (NLCs) is presented. We observed linearly polarized light, the orientation of which is in proximity to the bisection between the polarization direction at the maximal scattering in NLCs and the nematic director. Any arbitrary linear polarization of RLs can be obtained by rotating the NLC sample. The efficiency and output uniformity over the complete direction angle of 2π can be optimized by choosing a proper pump polarization.