Effect of recording-beam ratio on diffraction efficiency of polarization holographic gratings in dye-doped liquid-crystal films.

The +1 order diffraction of polarization holographic gratings generated by two linear orthogonally polarized writing beams in dye-doped liquid-crystal films were increased by using two recording beams with unequal intensity. The maximum diffraction efficiency of the polarization holograms in our experimental sample can reach 23% when the intensity ratio of two recording beams is 7:1, and this value is almost triple that when the intensity ratio of two recording beams is 1:1.