Talk:Photorefractive effect

what is the major difference between Two-beam Coupling and Two-wave mixing. How do you distinguish one from the other

Mechanism

Stage 1 says "A photorefractive material is illuminated by coherent beams of light". IMHO this is not quite correct, the light does not need to be coherent. --Ahellwig (talk) 19:19, 8 July 2010 (UTC)

You need the coherence for a stable interference pattern. Without that it is like having only one beam. Since the photorefractive effect works best with a very inhomogeneous illumination, one typically uses an interference pattern. --Danh (talk) 15:10, 9 July 2010 (UTC)