Document Abstract
In the photorefractive wave-mixing system, fluctuation in the signal beam intensity of the photorefrac
tive output with a reflection grating has been analyzed by employing pump feedback method. In this
method, fluctuations of the photorefractive wave-mixing process not only induce the intensity fluctua
tion of the mixing waves but also induce phase fluctuation of the mixing waves. Thus, the phase of the
pump and signal beams at the output surface fluctuates in time around a mean value. Using such a posi
tive feedback method of a pump beams, therelative fluctuation in the photorefractive output signal beam
intensity with respect to its mean intensity can be minimized significantly without reducing its mean
intensity. The factors that control the fluctuation in the signal beam intensity, such as the phase
f
luctuation of the output pump beam, absorption strength of the material and the feedback reflectivity
of the cavity mirrors, on the relative fluctuation of the output signal intensity in the photorefractive
wave-mixing systems have been studied in detail. It has been found that the fluctuation of the output
signal intensity relative to its mean intensity in the photorefractive wave-mixing system can be sup
pressed to larger extent by taking lower value of feedback reflectivity of the cavity mirrors which could
exist at a higher value of absorption strength of the photorefractive materials.