The photorefractive effect is a phenomenon whereby the local index of refraction is modified by spatial variations of the light intensity. It is strongly observed when coherent rays interfere with each other in a photorefractive material which forms a spatially varying pattern of illumination. The effect can be used to store temporary, erasable holograms and is useful for holographic data storage. It can also be used to create a phase-conjugate mirror or an optical spatial soliton.
We have capabilities to grow various dopant concentration of these laser crystals: