Photorefractive resonators exhibit an extremely small frequency difference (Δω/ω ~ 10−15) between the oscillating and pumping beams. The observed frequency difference is proportional to cavity-length detuning. This dependence is explained by a photorefractive phase shift that is due to slightly nondegenerate two-wave mixing that compensates for cavity detuning and satisfies the round-trip phase condition for steady-state oscillation. The measured onset or threshold of oscillation as a function of photorefractive gain and intensity agrees with theory.
© 1985 Optical Society of America
Original Manuscript: April 22, 1985
Manuscript Accepted: July 22, 1985
Published: October 1, 1985
M. D. Ewbank and P. Yeh, "Frequency shift and cavity length in photorefractive resonators," Opt. Lett. 10, 496-498 (1985)