Optical nonlinearity of pure lithium niobate crystals and hologram recording at low temperatures
Odulov S. G., Oleinik O. I., Soskin M. S.
The photoinduced change in the refractive index increases sharply when nominally pure lithium niobate crystals are cooled to liquid-nitrogen temperature. Study of the diffraction by photoinduced gratings shows that the reason for the sharp increase is the formation of space charge by a photovoltaic effect.