Temperature dependence of light‐induced scattering in a Ce:Fe:LiNbO₃ photorefractive crystal

Abstract

Light-induced scattering in a Ce:Fe:LiNbO 3 crystal is highly temperature dependent. By considering the effect due to thermally activated ions in a photorefractive crystal, we have shown that the photoinduced space-charge field is neutralized by the activated ions. This neutralization in turn leads to a reduction of scattering noise in the crystal. By raising the crystal temperature, we have observed a reduction in scattering noise, which is consistent with our prediction. The signal-to-noise ratio (SNR) in a two-wave mixing amplification due to thermal activation effect is analyzed. Experimental demonstrations using a Ce:Fe:LiNbO 3 crystal are provided in which we have shown that the SNR improves as the crystal temperature increases. © 1996 Society of Photo-Optical Instrumentation Engineers.

A method to remotely measure temperature change in a lithium niobate crystal using birefringence

“…This is due to beam fanning in the lithium niobate crystal. Beam fanning (or light induced scattering) is a phenomenon that originates from the amplification of scattered radiation as the light field traverses the photorefractive medium [15,16]. Consequently, this process reduces the amount of light travelling in the original beam direction and as such can be treated like other loss processes such as absorption.…”

“…The effect becomes worse with increasing exposure time, since scattered light is itself amplified, causing more scattering, and so on. Beam fanning is a photorefractive effect that is temperature dependent because as the material temperature is increased, hydrogen ions (protons) become mobile and tend to negate the effects of the photorefractive index change [16]. Thus in our treatment of the beam fanning term, beam fanning has both a time and temperature dependence.…”

Defect structure and optical damage resistance of Zr:Ce:Fe:LiNbO3crystals

“…The crystal is easily grown in large dimension from a melt of congruent composition by the Czochralski technique, and it has high diffraction efficiency and long information conservation time [4] . However, its applications in holographic memory devices are severely limited because of lower optical damage resistance [5,6] . Doped with the optical damage resistant additives like Mg, Zn, In and Sc [7][8][9][10] ，the laser-induced optical damage of LiNbO 3 can be greatly degraded Recently, Zr was reported to be a light-induced scattering resistance impurity, and it was more effective to suppress the light-induced scattering than other elements [11] .…”