|Strohriegl, P.; Kitzerow, H.-S.; Paelke, L.: Photorefractive polymer-dispersed liquid crystal based on a photoconducting polysiloxane, Applied Physics Letters, 86(3), 031104 (2005) -- DOI: 10.1063/1.1852082|
The photorefractive effect in a photoconducting polymer containing small liquid crystal droplets is studied. Two beam coupling experiments indicate a high optical gain at moderate field strength (>50 cm(-1) at 10 V/mum). The writing of photorefractive gratings is reversible. The dynamic behavior can be described by a two step process of the grating formation, the faster time constants being of the order of 100 ms. Modulation of the external voltage indicates that the reorientation of the director in the liquid crystals droplets is faster than the rise and decay times of the space charge field.