Theory of critical enhancement of photorefractive beam coupling.
We develop the idea of critical enhancement of the photorefractive response near the threshold of parametric excitation of space-charge waves (the spatial subharmonics) taking into account the vectorial character of beam coupling and a fairly strong broadening of the nonlinear resonance owing to light absorption. The results of our calculations are a description of the measurable characteristics of critical enhancement and optimization of the experimental conditions for detection of anomalously high amplification gain factors in cubic Bi(12)SiO(20) crystals.
Podivilov
E V
EV
International Institute for Nonlinear Studies, Koptyug Avenue 1, 630090 Novosibirsk, Russia.
Sturman
B I
BI
Gorkunov
M V
MV
Kamenov
V P
VP
Ringhofer
K H
KH