G. S. Agarwal, A. T. Friberg, and E. Wolf, "Elimination of distortions by phase conjugation without losses or gains," Opt. Commun. 43, 446–450 (1982).

G. S. Agarwal, "Dipole radiation in the presence of a phase conjugate mirror," Opt. Commun. 42, 205–207 (1982).

G. S. Agarwal and E. Wolf, "Theory of phase conjugation with weak scatterers," J. Opt. Soc. Am. 72, 321–326 (1982).

G. S. Agarwal, A. T. Friberg, and E. Wolf, "Effect of backscattering in phase conjugation with weak scatterers," J. Opt. Soc. Am. 72, 861–863 (1982).

B. Ya. Zel'dovich and V. V. Shkunov, "Spatial-polarization wavefront reversal in four-photon interaction," Sov. J. Quantum Electron. 9, 379–381 (1979); B. Ya. Zel'dovich and T. V. Yakovleva, "Spatial-polarization wavefront reversal in stimulated scattering of the Rayleigh line wing," Sov. J. Quantum Electron. 10, 501–505 (1980).

For reviews of the technique of optical phase conjugation see, for example, A. Yariv, "Phase conjugate optics and real-time holography," IEEE J. Quantum Electron. QE-14, 650–660 (1978); D. M. Pepper, "Nonlinear optical phase conjugation," Opt. Eng. 21, 156–183 (1982).

See, for example, B. Ya. Zel'dovich, V. I. Popovichev, V. V. Ragul'skii, and F. S. Faizullov, "Connection between the wave fronts of the reflected and exciting light in stimulated Mandel'shtam– Brillouin scattering," Sov. Phys. JETP 15, 109–113 (1972); O. Yu. Nosach, V. I. Popovichev, V. V. Ragul'skii, and F. S. Faizullov, "Cancellation of phase distortions in an amplifying medium with a 'Brillouin mirror,' " Sov. Phys. JETP 16, 435–438 (1972); D. N. Bloom and G. C. Bjorklund, "Conjugate wave-front generation and image reconstruction by four-wave mixing," Appl. Phys. Lett. 31, 592–594 (1977); and V. Wang and C. R. Guiliano, "Correction of phase aberrations via stimulated Brillouin scattering," Opt. Lett. 2, 4–6 (1978).

G. S. Agarwal, A. T. Friberg, and E. Wolf, "Elimination of distortions by phase conjugation without losses or gains," Opt. Commun. 43, 446–450 (1982).

G. S. Agarwal and E. Wolf, "Theory of phase conjugation with weak scatterers," J. Opt. Soc. Am. 72, 321–326 (1982).

G. S. Agarwal, A. T. Friberg, and E. Wolf, "Effect of backscattering in phase conjugation with weak scatterers," J. Opt. Soc. Am. 72, 861–863 (1982).

G. S. Agarwal, "Dipole radiation in the presence of a phase conjugate mirror," Opt. Commun. 42, 205–207 (1982).

See, for example, A. Baños, Dipole Radiation in the Presence of a Conducting Half-Space (Pergamon, Oxford, 1966), Eq. (2.19).

See, for example, B. Ya. Zel'dovich, V. I. Popovichev, V. V. Ragul'skii, and F. S. Faizullov, "Connection between the wave fronts of the reflected and exciting light in stimulated Mandel'shtam– Brillouin scattering," Sov. Phys. JETP 15, 109–113 (1972); O. Yu. Nosach, V. I. Popovichev, V. V. Ragul'skii, and F. S. Faizullov, "Cancellation of phase distortions in an amplifying medium with a 'Brillouin mirror,' " Sov. Phys. JETP 16, 435–438 (1972); D. N. Bloom and G. C. Bjorklund, "Conjugate wave-front generation and image reconstruction by four-wave mixing," Appl. Phys. Lett. 31, 592–594 (1977); and V. Wang and C. R. Guiliano, "Correction of phase aberrations via stimulated Brillouin scattering," Opt. Lett. 2, 4–6 (1978).

G. S. Agarwal, A. T. Friberg, and E. Wolf, "Effect of backscattering in phase conjugation with weak scatterers," J. Opt. Soc. Am. 72, 861–863 (1982).

G. S. Agarwal, A. T. Friberg, and E. Wolf, "Elimination of distortions by phase conjugation without losses or gains," Opt. Commun. 43, 446–450 (1982).

A. T. Friberg, "Integral equation of the scattered field in the presence of a phase-conjugate mirror" J. Opt. Soc. Am. (to be published.)

See, for example, B. Ya. Zel'dovich, V. I. Popovichev, V. V. Ragul'skii, and F. S. Faizullov, "Connection between the wave fronts of the reflected and exciting light in stimulated Mandel'shtam– Brillouin scattering," Sov. Phys. JETP 15, 109–113 (1972); O. Yu. Nosach, V. I. Popovichev, V. V. Ragul'skii, and F. S. Faizullov, "Cancellation of phase distortions in an amplifying medium with a 'Brillouin mirror,' " Sov. Phys. JETP 16, 435–438 (1972); D. N. Bloom and G. C. Bjorklund, "Conjugate wave-front generation and image reconstruction by four-wave mixing," Appl. Phys. Lett. 31, 592–594 (1977); and V. Wang and C. R. Guiliano, "Correction of phase aberrations via stimulated Brillouin scattering," Opt. Lett. 2, 4–6 (1978).

See, for example, B. Ya. Zel'dovich, V. I. Popovichev, V. V. Ragul'skii, and F. S. Faizullov, "Connection between the wave fronts of the reflected and exciting light in stimulated Mandel'shtam– Brillouin scattering," Sov. Phys. JETP 15, 109–113 (1972); O. Yu. Nosach, V. I. Popovichev, V. V. Ragul'skii, and F. S. Faizullov, "Cancellation of phase distortions in an amplifying medium with a 'Brillouin mirror,' " Sov. Phys. JETP 16, 435–438 (1972); D. N. Bloom and G. C. Bjorklund, "Conjugate wave-front generation and image reconstruction by four-wave mixing," Appl. Phys. Lett. 31, 592–594 (1977); and V. Wang and C. R. Guiliano, "Correction of phase aberrations via stimulated Brillouin scattering," Opt. Lett. 2, 4–6 (1978).

This integral equation is derived, in the context of time-independent quantum-mechanical potential scattering, for example in P. Roman, Advanced Quantum Theory (Addison-Wesley, Reading, Mass., 1965), Sec. 3.2.

B. Ya. Zel'dovich and V. V. Shkunov, "Spatial-polarization wavefront reversal in four-photon interaction," Sov. J. Quantum Electron. 9, 379–381 (1979); B. Ya. Zel'dovich and T. V. Yakovleva, "Spatial-polarization wavefront reversal in stimulated scattering of the Rayleigh line wing," Sov. J. Quantum Electron. 10, 501–505 (1980).

See, for example, C.-T. Tai, Dyadic Green's Functions in Electromagnetic Theory (Intext, Scranton, Pa., 1971), Sec. 14.

In this connection, see V. I. Tatarskii, The Effects of the Turbulent Atmosphere on Wave Propagation (National Technical Information Service, Springfield, Va., 1971); E. Wolf, "New theory of partial coherence in the space-frequency domain. Part I: spectra and cross spectra of steady-state sources," J. Opt. Soc. Am. 72, 343–351 (1982).

G. S. Agarwal and E. Wolf, "Theory of phase conjugation with weak scatterers," J. Opt. Soc. Am. 72, 321–326 (1982).

G. S. Agarwal, A. T. Friberg, and E. Wolf, "Elimination of distortions by phase conjugation without losses or gains," Opt. Commun. 43, 446–450 (1982).

G. S. Agarwal, A. T. Friberg, and E. Wolf, "Effect of backscattering in phase conjugation with weak scatterers," J. Opt. Soc. Am. 72, 861–863 (1982).

E. Wolf, "Phase conjugacy and symmetries in spatially bandlimited wavefields containing no evanescent components," J. Opt. Soc. Am. 70, 1311–1319 (1980). Equation (2.1) of this reference contains a misprint. *U*^{(2)}(*x*, *y*, *z*)*e*^{iωt} should be replaced with *U*^{(2)}(*x*, *y*, *z*)*e*^{-iωt}. Also, Eq. (1.8) should read *A*(*u*/*k*, *v*/*k*) = *k*^{2}*Ũ*(*u*, *v*; *z*)*e*^{-iωz}. These corrections do not-affect any other equations or conclusions of that paper.

For reviews of the technique of optical phase conjugation see, for example, A. Yariv, "Phase conjugate optics and real-time holography," IEEE J. Quantum Electron. QE-14, 650–660 (1978); D. M. Pepper, "Nonlinear optical phase conjugation," Opt. Eng. 21, 156–183 (1982).

See, for example, B. Ya. Zel'dovich, V. I. Popovichev, V. V. Ragul'skii, and F. S. Faizullov, "Connection between the wave fronts of the reflected and exciting light in stimulated Mandel'shtam– Brillouin scattering," Sov. Phys. JETP 15, 109–113 (1972); O. Yu. Nosach, V. I. Popovichev, V. V. Ragul'skii, and F. S. Faizullov, "Cancellation of phase distortions in an amplifying medium with a 'Brillouin mirror,' " Sov. Phys. JETP 16, 435–438 (1972); D. N. Bloom and G. C. Bjorklund, "Conjugate wave-front generation and image reconstruction by four-wave mixing," Appl. Phys. Lett. 31, 592–594 (1977); and V. Wang and C. R. Guiliano, "Correction of phase aberrations via stimulated Brillouin scattering," Opt. Lett. 2, 4–6 (1978).

B. Ya. Zel'dovich and V. V. Shkunov, "Spatial-polarization wavefront reversal in four-photon interaction," Sov. J. Quantum Electron. 9, 379–381 (1979); B. Ya. Zel'dovich and T. V. Yakovleva, "Spatial-polarization wavefront reversal in stimulated scattering of the Rayleigh line wing," Sov. J. Quantum Electron. 10, 501–505 (1980).

For reviews of the technique of optical phase conjugation see, for example, A. Yariv, "Phase conjugate optics and real-time holography," IEEE J. Quantum Electron. QE-14, 650–660 (1978); D. M. Pepper, "Nonlinear optical phase conjugation," Opt. Eng. 21, 156–183 (1982).

G. S. Agarwal, "Dipole radiation in the presence of a phase conjugate mirror," Opt. Commun. 42, 205–207 (1982).

G. S. Agarwal, A. T. Friberg, and E. Wolf, "Elimination of distortions by phase conjugation without losses or gains," Opt. Commun. 43, 446–450 (1982).

B. Ya. Zel'dovich and V. V. Shkunov, "Spatial-polarization wavefront reversal in four-photon interaction," Sov. J. Quantum Electron. 9, 379–381 (1979); B. Ya. Zel'dovich and T. V. Yakovleva, "Spatial-polarization wavefront reversal in stimulated scattering of the Rayleigh line wing," Sov. J. Quantum Electron. 10, 501–505 (1980).

See, for example, B. Ya. Zel'dovich, V. I. Popovichev, V. V. Ragul'skii, and F. S. Faizullov, "Connection between the wave fronts of the reflected and exciting light in stimulated Mandel'shtam– Brillouin scattering," Sov. Phys. JETP 15, 109–113 (1972); O. Yu. Nosach, V. I. Popovichev, V. V. Ragul'skii, and F. S. Faizullov, "Cancellation of phase distortions in an amplifying medium with a 'Brillouin mirror,' " Sov. Phys. JETP 16, 435–438 (1972); D. N. Bloom and G. C. Bjorklund, "Conjugate wave-front generation and image reconstruction by four-wave mixing," Appl. Phys. Lett. 31, 592–594 (1977); and V. Wang and C. R. Guiliano, "Correction of phase aberrations via stimulated Brillouin scattering," Opt. Lett. 2, 4–6 (1978).

Alternatively, by using the Maxwell equation ∇ · **D** = 0 (where **D** ≡ **E** + 4π**P** is the electric displacement vector), the constitutive relation **D** = *n*^{2}**E** and the vector identity ∇ · (*n*^{2}**E**) = *n*^{2}∇ · **E** + **E** · ∇*n*^{2}, Eq. (7.2) may be rewritten in the familiar form [equation] However, form (7.2) is more convenient for the present purposes.

See, for example, C.-T. Tai, Dyadic Green's Functions in Electromagnetic Theory (Intext, Scranton, Pa., 1971), Sec. 14.

In this connection, see V. I. Tatarskii, The Effects of the Turbulent Atmosphere on Wave Propagation (National Technical Information Service, Springfield, Va., 1971); E. Wolf, "New theory of partial coherence in the space-frequency domain. Part I: spectra and cross spectra of steady-state sources," J. Opt. Soc. Am. 72, 343–351 (1982).

Several schemes, such as those based on three-wave mixing [A. Yariv, "Three-dimensional pictorial transmission in optical fibers," Appl. Phys. Lett. 28,88–89 (1976)], four-wave mixing [R. W. Hellwarth, "Generation of time-reversed wave fronts by nonlinear refraction," J. Opt. Soc. Am. 67, 1–3 (1977)], stimulated Brillouin scattering (Zel'dovich *et al.*^{2}), etc. have been proposed and used for the generation of the conjugated field. The polarization properties of the conjugated field will, in general, be different from those of the incident (probe) field. A complete reversal of polarization can be achieved by suitably arranging the experimental geometry and by choosing the polarization properties of the various interacting waves appropriately [see, for example, Ref. 16 below and J. F. Lam, D. G. Steel, R. A. McFarlane, and R. C. Lind, "Atomic coherence effects in resonant degenerate four-wave mixing," Appl. Phys. Lett. 38, 977–979 (1981)].

This integral equation is derived, in the context of time-independent quantum-mechanical potential scattering, for example in P. Roman, Advanced Quantum Theory (Addison-Wesley, Reading, Mass., 1965), Sec. 3.2.

The concept of a PCM is a convenient idealization that describes the effect of a true physical device located beyond the plane *z* = *z*_{1}, by means of which a field distribution *U* is replaced by a new field distribution µ*U** in that plane. The transformation *U* → µ*U** is usually achieved by nonlinear optical interactions, such as stimulated scattering processes or optical parametric interactions [see Ref. 1].

The term "conjugate" (or "conjugated") field is somewhat ambigous and must be interpreted with caution. The field *U*_{c}(**r**) is generated as a result of the interaction of the incident field *U*^{(i)}(**r**) with the scattering medium in the presence of the PCM. In general, it will include, in addition to *U*^{(i)}(**r**), also contributions (usually ignored) arising from backscattering of the incident field and from successive conjugations of waves backscattered onto the PCM [see, for example, Figs. 3(a), 3(d), 4(a), and 4(h)].

For a discussion of some of the complications that arise when the evanescent waves are taken into account, see E. Wolf and W. H. Carter, "Comments on the theory of phase-conjugated waves," Opt. Commun. 40, 397–400 (1982). The approximation resulting from the neglection of the evanescent waves in the scattered field is examined, within the accuracy of the first Born approximation, in App. A of Ref. 3.

A. T. Friberg, "Integral equation of the scattered field in the presence of a phase-conjugate mirror" J. Opt. Soc. Am. (to be published.)

Throughout this paper, a caret above a symbol denotes an operator.

See, for example, A. Baños, Dipole Radiation in the Presence of a Conducting Half-Space (Pergamon, Oxford, 1966), Eq. (2.19).

We will not discuss here the conditions under which series (3.1) will converge, a subject that would require a separate investigation.

E. Wolf, "Phase conjugacy and symmetries in spatially bandlimited wavefields containing no evanescent components," J. Opt. Soc. Am. 70, 1311–1319 (1980). Equation (2.1) of this reference contains a misprint. *U*^{(2)}(*x*, *y*, *z*)*e*^{iωt} should be replaced with *U*^{(2)}(*x*, *y*, *z*)*e*^{-iωt}. Also, Eq. (1.8) should read *A*(*u*/*k*, *v*/*k*) = *k*^{2}*Ũ*(*u*, *v*; *z*)*e*^{-iωz}. These corrections do not-affect any other equations or conclusions of that paper.