Gaussian transverse eigenmodes of a stimulated scattering phase-conjugate resonator are calculated. The experimental setup which provides the stimulated scattering phase-conjugate resonator is described.
We review the history and nature of stimulated scattering of optical beams and of the large phase-conjugate component often observed in stimulated backscattering, whether it be of Raman, Brillouin, Rayleigh, or other origin. We review the theory of the magnitude of the phase-conjugate component in stimulated backscattering of waves in a multimode optical guide (the usual experimental configuration) or in free focus. Wide applicability of stimulated backscattering for optical phase conjugation is found.
Various aspects of optical phase conjugation are discussed: the properties of the conjugate wave, its potential applications, the basic conjugation methods, and a brief history of the question. The theory for phase conjugation in stimulated scattering is set forth in detail. The basic experimental results on this conjugation method are also discussed in detail. Phase conjugation occurs because that configuration of the back-scattered field which has the conjugate wavefront is amplified to the greatest extent (at a doubled gain) in the intense speckle-inhomogeneous conjugate wave in a medium in which stimulated scattering occurs. Because of the large overall amplification in stimulated scattering, all the other, uncorrelated, configurations of the spontaneously scattered nucleating waves are amplified by a factor of 107 less and are discriminated against. The intervals of values of the various parameters in which the conjugate configuration (the specklon) exists are discussed theoretically, as is the effect of nonlinear selection and saturation on phase conjugation in stimulated scattering. There is a review of experimental results on the first observation of the effect, on the measurement of the angular structure of the uncorrelated waves and of the extent to which they are discriminated against, on the phase fluctuations of the conjugate wave, on the conjugation of subthreshold and depolarized radiation, and on phase conjugation in stimulated scattering in focused beams and for other scattered-wave amplification mechanisms.