Thin dynamic holograms with an asymmetric fringe profile

Results of an investigation and a comparison of schemes used for recording dynamic holographic gratings in a liquid-crystal spatial light modulator, which ensure grating profile asymmetrization and, thus, a significant increase in its diffraction efficiency, are presented. Three approaches are considered: digital, analog, and self-asymmetrization of the profile due to the effect of a secondary field induced in the nematic volume. It is demonstrated that the first two approaches provide recording of gratings with low spatial frequencies (several mm − 1) and with an approximately equal rate of asymmetry (the potential efficiency of diffraction to the first order is 70–75%), while the third approach provides recording of gratings with a much higher spatial frequency (hundreds of mm − 1), but with a lower efficiency (about 50%).