On the Coherent and Incoherent Image Conversion in Hybrid Polymer Liquid Crystal Structures

Abstract

We report on the new hybrid photonic devices exhibiting photorefactive type behaviour. These devices known as hybrid polymer - liquid crystal structures (HPLCS) are composed of a nearly transparent thin photoconducting polymeric layer and a nematic liquid crystal layer. In such structures an efficient coherent light amplification with a very high net exponential gain has been observed in a degenerate two-wave coupling process. The amplification results from an energy exchange between inciding beams due to diffraction on nonlocal refractive index grating formed in liquid crystal layer by molecular reorientation mechanism. HPLCS’s allow also for incoherent-to-coherent image conversion. In this work we focus our attention on important issues limiting their performances in some practically important optical systems where these devices can be used.