L. Fu-Li, J. A. Hermann, and J. N. Elgin, "Effects of two-photon optical bistability upon phase conjugation," Opt. Commun. 40, 446–450 (1982).

A. Borshch, M. Brodin, V. Volkov, and N. Kukhtarev, "Optical bistability and hysteresis in phase conjugation by degenerate six-photon mixing," Opt. Commun. 41, 213–215 (1982).

G. P. Agrawal, J. L. Boulnois, P. Aubourg, and A. van Lerberghe, "Saturation splitting in the spectrum of resonant degenerate four-wave mixing," Opt. Lett. 7, 540–542 (1982).

J. Mlynek, F. Mitschke, R. Deserno, and W. Lange, "Optical bistability by transverse optical pumping," Appl. Phys. B 28, 135 (1982).

P. Aubourg, J. P. Bettini, G. P. Agrawal, P. Cottin, D. Guérin, O. Meunier, and J. L. Boulnois, "Doppler-free cw phase-conjugate spectrum of SF_{6} by resonant degenerate four-wave mixing at 10.6 µm," Opt. Lett. 6, 383–385 (1981).

D. G. Steel and J. F. Lam, "Saturation effects and inhomogeneous broadening in Doppler-free degenerate four-wave mixing," Opt. Commun. 40, 77–80 (1981).

G. P. Agrawal, "Phase conjugation and degenerate four-wave mixing in three-level systems," IEEE J. Quantum Electron. QE-17, 2335–2340 (1981).

G. P. Agrawal and C. Flytzanis, "Bistability and hysteresis in phase-conjugated reflectivity," IEEE J. Quantum Electron. QE-14, 374–380 (1981).

G. P. Agrawal, C. Flytzanis, R. Frey, and F. Pradere, "Bistable reflectivity of phase-conjugated signal through intracavity degenerate four-wave mixing," Appl. Phys. Lett. 38, 492–494 (1981).

T. Fu and M. Sargent III, "Theory of two-photon phase conjugation," Opt. Lett. 5, 433–435 (1980).

D. F. Walls and P. Zoller, "A coherent nonlinear mechanism for optical bistability from three-level atoms," Opt. Commun. 34, 260–264 (1980).

G. P. Agrawal and H. J. Carmichael, "Inhomogeneous broadening and the mean-field approximation for optical bistability in a Fabry–Perot," Opt. Acta. 27, 651–660 (1980).

R. K. Raj, D. Bloch, J. J. Snyder, G. Camy, and M. Ducloy, "High-frequency optically heterodyned saturation spectroscopy via resonant degenerate four-wave mixing," Phys. Rev. Lett. 44, 1251–1254 (1980).

C. Flytzanis and C. L. Tang, "Light-induced critical behavior in four-wave interaction in nonlinear systems," Phys. Rev. Lett. 45, 441–444 (1980).

H. G. Winful and J. H. Marburger, "Hysteresis and optical bistability in degenerate four-wave mixing," Appl. Phys. Lett. 36, 613–614 (1980).

G. P. Agrawal and H. J. Carmichael, "Optical bistability through nonlinear dispersion and absorption," Phys. Rev. A 19, 2074–2086 (1979).

R. Bonifacio and L. A. Lugiato, "Optical bistability and cooperative effects in resonance fluorescence," Phys. Rev. A 18, 1129–1144 (1978).

P. F. Liao, D. M. Bloom, and N. P. Economou, "Cw optical wave-front conjugation by saturated absorption in atomic sodium vapor," Appl. Phys. Lett. 32, 813–815 (1978).

In some of the early experiments on phase conjugation, the laser cavity of the pump wave itself was used. See E. F. Bergmann, I. J. Bigio, B. J. Feldman, and R. A. Fisher, "High-efficiency pulsed 10.6-µm phase-conjugate reflection via degenerate fourwave mixing," Opt. Lett. 3, 82–84 (1978).

H. R. Gray, R. M. Whitley, and C. R. Stroud, "Coherent trapping of atomic populations," Opt. Lett. 3, 218–220 (1978).

H. M. Gibbs, S. L. McCall, and T. N. C. Venkatesan, "Differential gain and bistability using a sodium-filled Fabry–Perot interferometer," Phys. Rev. Lett. 36, 1135–1138 (1976).

R. G. Brewer and E. L. Hahn, "Coherent two-photon processes: transient and steady-state cases," Phys. Rev. A 11, 1641–1649 (1975).

R. L. Abrams and R. C. Lind, "Degenerate four-wave mixing in absorbing media," Opt. Lett. 2, 94–96 (1978); errata, Opt. Lett. 3, 205 (1978).

G. P. Agrawal, J. L. Boulnois, P. Aubourg, and A. van Lerberghe, "Saturation splitting in the spectrum of resonant degenerate four-wave mixing," Opt. Lett. 7, 540–542 (1982).

P. Aubourg, J. P. Bettini, G. P. Agrawal, P. Cottin, D. Guérin, O. Meunier, and J. L. Boulnois, "Doppler-free cw phase-conjugate spectrum of SF_{6} by resonant degenerate four-wave mixing at 10.6 µm," Opt. Lett. 6, 383–385 (1981).

G. P. Agrawal, "Phase conjugation and degenerate four-wave mixing in three-level systems," IEEE J. Quantum Electron. QE-17, 2335–2340 (1981).

G. P. Agrawal and C. Flytzanis, "Bistability and hysteresis in phase-conjugated reflectivity," IEEE J. Quantum Electron. QE-14, 374–380 (1981).

G. P. Agrawal, C. Flytzanis, R. Frey, and F. Pradere, "Bistable reflectivity of phase-conjugated signal through intracavity degenerate four-wave mixing," Appl. Phys. Lett. 38, 492–494 (1981).

G. P. Agrawal and H. J. Carmichael, "Inhomogeneous broadening and the mean-field approximation for optical bistability in a Fabry–Perot," Opt. Acta. 27, 651–660 (1980).

G. P. Agrawal and H. J. Carmichael, "Optical bistability through nonlinear dispersion and absorption," Phys. Rev. A 19, 2074–2086 (1979).

C. Flytzanis, G. P. Agrawal, and C. L. Tang, "Critical behavior in optical phase conjugation," in Lasers and Their Applications, W. O. N. Guimaraes, C.-T. Lin, and A. Mooradian, eds. (Springer-Verlag, Berlin, 1981).

G. P. Agrawal, J. L. Boulnois, P. Aubourg, and A. van Lerberghe, "Saturation splitting in the spectrum of resonant degenerate four-wave mixing," Opt. Lett. 7, 540–542 (1982).

P. Aubourg, J. P. Bettini, G. P. Agrawal, P. Cottin, D. Guérin, O. Meunier, and J. L. Boulnois, "Doppler-free cw phase-conjugate spectrum of SF_{6} by resonant degenerate four-wave mixing at 10.6 µm," Opt. Lett. 6, 383–385 (1981).

R. K. Raj, D. Bloch, J. J. Snyder, G. Camy, and M. Ducloy, "High-frequency optically heterodyned saturation spectroscopy via resonant degenerate four-wave mixing," Phys. Rev. Lett. 44, 1251–1254 (1980).

P. F. Liao, D. M. Bloom, and N. P. Economou, "Cw optical wave-front conjugation by saturated absorption in atomic sodium vapor," Appl. Phys. Lett. 32, 813–815 (1978).

R. Bonifacio and L. A. Lugiato, "Optical bistability and cooperative effects in resonance fluorescence," Phys. Rev. A 18, 1129–1144 (1978).

A. Borshch, M. Brodin, V. Volkov, and N. Kukhtarev, "Optical bistability and hysteresis in phase conjugation by degenerate six-photon mixing," Opt. Commun. 41, 213–215 (1982).

G. P. Agrawal, J. L. Boulnois, P. Aubourg, and A. van Lerberghe, "Saturation splitting in the spectrum of resonant degenerate four-wave mixing," Opt. Lett. 7, 540–542 (1982).

P. Aubourg, J. P. Bettini, G. P. Agrawal, P. Cottin, D. Guérin, O. Meunier, and J. L. Boulnois, "Doppler-free cw phase-conjugate spectrum of SF_{6} by resonant degenerate four-wave mixing at 10.6 µm," Opt. Lett. 6, 383–385 (1981).

R. G. Brewer and E. L. Hahn, "Coherent two-photon processes: transient and steady-state cases," Phys. Rev. A 11, 1641–1649 (1975).

A. Borshch, M. Brodin, V. Volkov, and N. Kukhtarev, "Optical bistability and hysteresis in phase conjugation by degenerate six-photon mixing," Opt. Commun. 41, 213–215 (1982).

R. K. Raj, D. Bloch, J. J. Snyder, G. Camy, and M. Ducloy, "High-frequency optically heterodyned saturation spectroscopy via resonant degenerate four-wave mixing," Phys. Rev. Lett. 44, 1251–1254 (1980).

G. P. Agrawal and H. J. Carmichael, "Inhomogeneous broadening and the mean-field approximation for optical bistability in a Fabry–Perot," Opt. Acta. 27, 651–660 (1980).

G. P. Agrawal and H. J. Carmichael, "Optical bistability through nonlinear dispersion and absorption," Phys. Rev. A 19, 2074–2086 (1979).

J. Mlynek, F. Mitschke, R. Deserno, and W. Lange, "Optical bistability by transverse optical pumping," Appl. Phys. B 28, 135 (1982).

R. K. Raj, D. Bloch, J. J. Snyder, G. Camy, and M. Ducloy, "High-frequency optically heterodyned saturation spectroscopy via resonant degenerate four-wave mixing," Phys. Rev. Lett. 44, 1251–1254 (1980).

P. F. Liao, D. M. Bloom, and N. P. Economou, "Cw optical wave-front conjugation by saturated absorption in atomic sodium vapor," Appl. Phys. Lett. 32, 813–815 (1978).

L. Fu-Li, J. A. Hermann, and J. N. Elgin, "Effects of two-photon optical bistability upon phase conjugation," Opt. Commun. 40, 446–450 (1982).

G. P. Agrawal, C. Flytzanis, R. Frey, and F. Pradere, "Bistable reflectivity of phase-conjugated signal through intracavity degenerate four-wave mixing," Appl. Phys. Lett. 38, 492–494 (1981).

G. P. Agrawal and C. Flytzanis, "Bistability and hysteresis in phase-conjugated reflectivity," IEEE J. Quantum Electron. QE-14, 374–380 (1981).

C. Flytzanis and C. L. Tang, "Light-induced critical behavior in four-wave interaction in nonlinear systems," Phys. Rev. Lett. 45, 441–444 (1980).

C. Flytzanis, G. P. Agrawal, and C. L. Tang, "Critical behavior in optical phase conjugation," in Lasers and Their Applications, W. O. N. Guimaraes, C.-T. Lin, and A. Mooradian, eds. (Springer-Verlag, Berlin, 1981).

G. P. Agrawal, C. Flytzanis, R. Frey, and F. Pradere, "Bistable reflectivity of phase-conjugated signal through intracavity degenerate four-wave mixing," Appl. Phys. Lett. 38, 492–494 (1981).

L. Fu-Li, J. A. Hermann, and J. N. Elgin, "Effects of two-photon optical bistability upon phase conjugation," Opt. Commun. 40, 446–450 (1982).

H. M. Gibbs, S. L. McCall, and T. N. C. Venkatesan, "Differential gain and bistability using a sodium-filled Fabry–Perot interferometer," Phys. Rev. Lett. 36, 1135–1138 (1976).

R. G. Brewer and E. L. Hahn, "Coherent two-photon processes: transient and steady-state cases," Phys. Rev. A 11, 1641–1649 (1975).

L. Fu-Li, J. A. Hermann, and J. N. Elgin, "Effects of two-photon optical bistability upon phase conjugation," Opt. Commun. 40, 446–450 (1982).

A. Borshch, M. Brodin, V. Volkov, and N. Kukhtarev, "Optical bistability and hysteresis in phase conjugation by degenerate six-photon mixing," Opt. Commun. 41, 213–215 (1982).

D. G. Steel and J. F. Lam, "Saturation effects and inhomogeneous broadening in Doppler-free degenerate four-wave mixing," Opt. Commun. 40, 77–80 (1981).

J. Mlynek, F. Mitschke, R. Deserno, and W. Lange, "Optical bistability by transverse optical pumping," Appl. Phys. B 28, 135 (1982).

P. F. Liao, D. M. Bloom, and N. P. Economou, "Cw optical wave-front conjugation by saturated absorption in atomic sodium vapor," Appl. Phys. Lett. 32, 813–815 (1978).

R. L. Abrams and R. C. Lind, "Degenerate four-wave mixing in absorbing media," Opt. Lett. 2, 94–96 (1978); errata, Opt. Lett. 3, 205 (1978).

R. Bonifacio and L. A. Lugiato, "Optical bistability and cooperative effects in resonance fluorescence," Phys. Rev. A 18, 1129–1144 (1978).

H. G. Winful and J. H. Marburger, "Hysteresis and optical bistability in degenerate four-wave mixing," Appl. Phys. Lett. 36, 613–614 (1980).

H. M. Gibbs, S. L. McCall, and T. N. C. Venkatesan, "Differential gain and bistability using a sodium-filled Fabry–Perot interferometer," Phys. Rev. Lett. 36, 1135–1138 (1976).

J. Mlynek, F. Mitschke, R. Deserno, and W. Lange, "Optical bistability by transverse optical pumping," Appl. Phys. B 28, 135 (1982).

J. Mlynek, F. Mitschke, R. Deserno, and W. Lange, "Optical bistability by transverse optical pumping," Appl. Phys. B 28, 135 (1982).

For a review see, for example, D. M. Pepper, "Nonlinear optical phase conjugation," Opt. Eng. 21, 155–183 (1982); see also R. A. Fisher, ed., Optical Phase Conjugation (Academic, New York, 1983).

G. P. Agrawal, C. Flytzanis, R. Frey, and F. Pradere, "Bistable reflectivity of phase-conjugated signal through intracavity degenerate four-wave mixing," Appl. Phys. Lett. 38, 492–494 (1981).

R. K. Raj, D. Bloch, J. J. Snyder, G. Camy, and M. Ducloy, "High-frequency optically heterodyned saturation spectroscopy via resonant degenerate four-wave mixing," Phys. Rev. Lett. 44, 1251–1254 (1980).

R. K. Raj, D. Bloch, J. J. Snyder, G. Camy, and M. Ducloy, "High-frequency optically heterodyned saturation spectroscopy via resonant degenerate four-wave mixing," Phys. Rev. Lett. 44, 1251–1254 (1980).

D. G. Steel and J. F. Lam, "Saturation effects and inhomogeneous broadening in Doppler-free degenerate four-wave mixing," Opt. Commun. 40, 77–80 (1981).

C. Flytzanis and C. L. Tang, "Light-induced critical behavior in four-wave interaction in nonlinear systems," Phys. Rev. Lett. 45, 441–444 (1980).

C. Flytzanis, G. P. Agrawal, and C. L. Tang, "Critical behavior in optical phase conjugation," in Lasers and Their Applications, W. O. N. Guimaraes, C.-T. Lin, and A. Mooradian, eds. (Springer-Verlag, Berlin, 1981).

H. M. Gibbs, S. L. McCall, and T. N. C. Venkatesan, "Differential gain and bistability using a sodium-filled Fabry–Perot interferometer," Phys. Rev. Lett. 36, 1135–1138 (1976).

A. Borshch, M. Brodin, V. Volkov, and N. Kukhtarev, "Optical bistability and hysteresis in phase conjugation by degenerate six-photon mixing," Opt. Commun. 41, 213–215 (1982).

D. F. Walls and P. Zoller, "A coherent nonlinear mechanism for optical bistability from three-level atoms," Opt. Commun. 34, 260–264 (1980).

H. G. Winful and J. H. Marburger, "Hysteresis and optical bistability in degenerate four-wave mixing," Appl. Phys. Lett. 36, 613–614 (1980).

D. F. Walls and P. Zoller, "A coherent nonlinear mechanism for optical bistability from three-level atoms," Opt. Commun. 34, 260–264 (1980).

J. Mlynek, F. Mitschke, R. Deserno, and W. Lange, "Optical bistability by transverse optical pumping," Appl. Phys. B 28, 135 (1982).

P. F. Liao, D. M. Bloom, and N. P. Economou, "Cw optical wave-front conjugation by saturated absorption in atomic sodium vapor," Appl. Phys. Lett. 32, 813–815 (1978).

G. P. Agrawal, C. Flytzanis, R. Frey, and F. Pradere, "Bistable reflectivity of phase-conjugated signal through intracavity degenerate four-wave mixing," Appl. Phys. Lett. 38, 492–494 (1981).

H. G. Winful and J. H. Marburger, "Hysteresis and optical bistability in degenerate four-wave mixing," Appl. Phys. Lett. 36, 613–614 (1980).

G. P. Agrawal and C. Flytzanis, "Bistability and hysteresis in phase-conjugated reflectivity," IEEE J. Quantum Electron. QE-14, 374–380 (1981).

G. P. Agrawal, "Phase conjugation and degenerate four-wave mixing in three-level systems," IEEE J. Quantum Electron. QE-17, 2335–2340 (1981).

G. P. Agrawal and H. J. Carmichael, "Inhomogeneous broadening and the mean-field approximation for optical bistability in a Fabry–Perot," Opt. Acta. 27, 651–660 (1980).

A. Borshch, M. Brodin, V. Volkov, and N. Kukhtarev, "Optical bistability and hysteresis in phase conjugation by degenerate six-photon mixing," Opt. Commun. 41, 213–215 (1982).

L. Fu-Li, J. A. Hermann, and J. N. Elgin, "Effects of two-photon optical bistability upon phase conjugation," Opt. Commun. 40, 446–450 (1982).

D. G. Steel and J. F. Lam, "Saturation effects and inhomogeneous broadening in Doppler-free degenerate four-wave mixing," Opt. Commun. 40, 77–80 (1981).

D. F. Walls and P. Zoller, "A coherent nonlinear mechanism for optical bistability from three-level atoms," Opt. Commun. 34, 260–264 (1980).

H. R. Gray, R. M. Whitley, and C. R. Stroud, "Coherent trapping of atomic populations," Opt. Lett. 3, 218–220 (1978).

P. Aubourg, J. P. Bettini, G. P. Agrawal, P. Cottin, D. Guérin, O. Meunier, and J. L. Boulnois, "Doppler-free cw phase-conjugate spectrum of SF_{6} by resonant degenerate four-wave mixing at 10.6 µm," Opt. Lett. 6, 383–385 (1981).

G. P. Agrawal, J. L. Boulnois, P. Aubourg, and A. van Lerberghe, "Saturation splitting in the spectrum of resonant degenerate four-wave mixing," Opt. Lett. 7, 540–542 (1982).

In some of the early experiments on phase conjugation, the laser cavity of the pump wave itself was used. See E. F. Bergmann, I. J. Bigio, B. J. Feldman, and R. A. Fisher, "High-efficiency pulsed 10.6-µm phase-conjugate reflection via degenerate fourwave mixing," Opt. Lett. 3, 82–84 (1978).

T. Fu and M. Sargent III, "Theory of two-photon phase conjugation," Opt. Lett. 5, 433–435 (1980).

R. Bonifacio and L. A. Lugiato, "Optical bistability and cooperative effects in resonance fluorescence," Phys. Rev. A 18, 1129–1144 (1978).

G. P. Agrawal and H. J. Carmichael, "Optical bistability through nonlinear dispersion and absorption," Phys. Rev. A 19, 2074–2086 (1979).

R. G. Brewer and E. L. Hahn, "Coherent two-photon processes: transient and steady-state cases," Phys. Rev. A 11, 1641–1649 (1975).

H. M. Gibbs, S. L. McCall, and T. N. C. Venkatesan, "Differential gain and bistability using a sodium-filled Fabry–Perot interferometer," Phys. Rev. Lett. 36, 1135–1138 (1976).

C. Flytzanis and C. L. Tang, "Light-induced critical behavior in four-wave interaction in nonlinear systems," Phys. Rev. Lett. 45, 441–444 (1980).

R. K. Raj, D. Bloch, J. J. Snyder, G. Camy, and M. Ducloy, "High-frequency optically heterodyned saturation spectroscopy via resonant degenerate four-wave mixing," Phys. Rev. Lett. 44, 1251–1254 (1980).

C. Flytzanis, G. P. Agrawal, and C. L. Tang, "Critical behavior in optical phase conjugation," in Lasers and Their Applications, W. O. N. Guimaraes, C.-T. Lin, and A. Mooradian, eds. (Springer-Verlag, Berlin, 1981).

For a review see, for example, D. M. Pepper, "Nonlinear optical phase conjugation," Opt. Eng. 21, 155–183 (1982); see also R. A. Fisher, ed., Optical Phase Conjugation (Academic, New York, 1983).

R. L. Abrams and R. C. Lind, "Degenerate four-wave mixing in absorbing media," Opt. Lett. 2, 94–96 (1978); errata, Opt. Lett. 3, 205 (1978).

It is not appropriate to use the term reflectivity spectrum because the laser frequency is kept fixed.

For the case of pulsed radiation, the analysis can be applied if the medium-response time is shorter than the duration of the optical pulse.

In the literature on optical bistability, this is often referred to as the mean-field approximation (see Refs. 8, 9, and 17).