A. Grunnetjepsen et al., SUBHARMONIC INSTABILITIES IN PHOTOREFRACTIVE CRYSTALS FOR AN APPLIED ALTERNATING ELECTRIC-FIELD - THEORETICAL-ANALYSIS, Journal of the Optical Society of America. B, Optical physics, 11(1), 1994, pp. 132-135
The spatial subharmonic instability arising from the material equation
s is investigated theoretically for both square and sinusoidal applied
alternating electric fields. The threshold conditions are given for t
he amplitude of the applied field as a function of the detuning freque
ncy, contrast of fundamental interference pattern, and interbeam angle
by the use of the temporal solutions for the amplitude of the space-c
harge field presented elsewhere [J. Opt. Soc. Am. B. 10, 124 (1993)] T
he different effects of the square wave and sinusoidal applied fields
for subharmonic generation are discussed.