Phase conjugacy of fields of stimulated scattering

Igor' M Bel'dyugin, E M Zemskov, V N Klushin +1 more

It is shown that wavefront reversal with a frequency shift is possible in axial anti-Stokes stimulated Raman scattering. The similarities and differences between this scheme and the phase conjugacy schemes proposed earlier are discussed. It is shown that the proposed scheme extends the class of processes in which wavefront reversal may be observed.

Boris Ya Zel'dovich, N. F. Pilipetskiǐ, Vladimir V. Shkunov

Genevieve Rivoire, A. I. Sokolovskaia

Edward J. Miller, Robert W. Boyd

Stimulated scattering is a nonlinear process that often results in the generation of a backwardgoing signal. This signal is known to display several unique and interesting properties; perhaps the most notable is phase conjugation. Stimulated Rayleigh-wing scattering (SRWS)1'2 is the stimulated scattering process arising from the optical Kerr effect, and it possesses an extremely fast response time (2 ps in CS2). Under certain experimental conditions, SRWS is known to conjugate both the phase and polarization of an incident field.3 The optical Kerr effect also leads to an intensity-dependent refractive index and is often the dominant contribution to this effect. With a large nonlinear index change, several undesirable effects, such as self-focusing and filamentation,Stimulated scattering is a nonlinear process that often results in the generation of a backwardgoing signal. This signal is known to display several unique and interesting properties; perhaps the most notable is phase conjugation. Stimulated Rayleigh-wing scattering (SRWS)1'2 is the stimulated scattering process arising from the optical Kerr effect, and it possesses an extremely fast response time (2 ps in CS2). Under certain experimental conditions, SRWS is known to conjugate both the phase and polarization of an incident field.3 The optical Kerr effect also leads to an intensity-dependent refractive index and is often the dominant contribution to this effect. With a large nonlinear index change, several undesirable effects, such as self-focusing and filamentation, occur as an intense optical wave propagates through a nonlinear medium.4

Boris Ya Zel'dovich, N. F. Pilipetskiǐ, Vladimir V. Shkunov

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.

V. V. Ragulsky