INFLUENCE OF THERMAL FLUCTUATION NOISE ON 2-WAVE MIXING IN SATURABLE ABSORBERS

We have extended the description of nonlinear optical two-wave mixing in a three-level saturable absorbing medium to include a noise contrib ution from thermally driven fluctuations in the real part of the refra ctive index. An effective gain factor is introduced to describe this i nfluence on the signal beam and numerical data are given for ruby. The se data, which include saturation, show that the influence of noise on the signal beam near the saturation gain value is more than ten times larger than that calculated using the theory for a Kerr medium for th e same gain value.