Liquid crystal light valve using bulk monocrystalline Bi12SiO20 as the photoconductive material

A new liquid crystal light valve (LCLV) is presented using bulk monocrystalline Bi(12)SiO(20) (BSO) as both the photoconductive material and as one of the substrates supporting the liquid crystal layer. The photo-conductive properties of the BSO under ac voltages are investigated. The device operates at room temperature with a low ac drive voltage (25-V ac at 500 Hz). These specific properties are explained from the aspect of an equivalent electrical circuit of the structure. A prototype BSO LCLV with a 15-mum liquid crystal thickness shows a 10-lp mm(-1) spatial resolution. The device coherent modulation transfer function was measured experimentally and found to agree with theory. Typical writing energies are approximately 20 microJ cm(-2) at wavelength lambda = 450 nm.