Showing papers on "Phase conjugation published in 1982"
TL;DR: Continuous-wave phase conjugation of an image-bearing beam is demonstrated using a single-domain crystal of BaTiO(3) and nothing else and has a phase-conjugate reflectivity of 30%.
Abstract: Continuous-wave phase conjugation of an image-bearing beam is demonstrated using a single-domain crystal of BaTiO(3) and nothing else. The device operates by four-wave mixing using the photorefractive effect but without any external pumping beams or external mirrors. The customary pumping beams are derived from the incident beam and are internally reflected inside the crystal adjacent to an edge. The device is self-starting and has a phase-conjugate reflectivity of 30%. Imaging applications are discussed.
698 citations
TL;DR: A review of photorefractive effects in electro-optic materials and their applications is presented in this paper, where the optimum parameters for applications such as volume hologram storage, coherent light amplification, optical phase conjugation etc.
608 citations
TL;DR: It is found that a phase-conjugate mirror with depleted pumps may exhibit bistability, and an exact solution of a nonlinear model of holographic four-wave mixing is derived.
Abstract: An exact solution of a nonlinear model of holographic four-wave mixing is derived. An expression for the reflectivity of a phase-conjugate mirror with depleted pumps is presented. We find that such a phase-conjugate mirror may exhibit bistability.
104 citations
TL;DR: By using the wave-front reversal properties of degenerate four-wave mixing, this work has compensated for the degradation of the image that is due to modal dispersion in a fiber.
Abstract: We have demonstrated image transmission through a multimode fiber by using optical phase conjugation. By using the wave-front reversal properties of degenerate four-wave mixing, we have compensated for the degradation of the image that is due to modal dispersion in a fiber.
95 citations
TL;DR: In this article, a theory of degenerate four-wave mixing in absorbing media is developed in terms of a general nonlinear susceptibility and the predictions of the theory are examined in both high and low reflectivity regimes and specific nonlinearity-inducing mechanisms of thermally induced refractive index changes, the Kerr effect, and saturable absorption are considered.
Abstract: A theory of degenerate four-wave mixing in absorbing media is developed in terms of a general nonlinear susceptibility. The predictions of the theory are examined in both high and low reflectivity regimes and the specific nonlinearity-inducing mechanisms of thermally induced refractive index changes, the Kerr effect, and saturable absorption are considered. Such a theory is of particular relevance to degenerate four-wave mixing experiments in the ultraviolet and the predictions of the theory are compared with results obtained from such experiments.
95 citations
TL;DR: In this paper, a review of various nonlinear optical mechanisms that may be used for DFWM, as well as the various DFWM and related "transient grating" experiments that have been performed for application to phase conjugation and to carrier dynamics studies are presented.
Abstract: Semiconductors appear to have excellent potential as materials for phase conjugation via degenerate four-wave mixing (DFWM) because of the large variety of nonlinear optical mechanisms that may be invoked in them. When the optical wavelength is near or above the band gap, mobile particles such as free electrons and holes or free excitons may be created; in such cases, DFWM itself provides a powerful contact-free and nondestructive technique for the study of carrier transport and decay parameters, such as ambipolar diffusion coefficients and recombination times. In this article, we briefly review the various nonlinear mechanisms that may be used for DFWM, as well as the various DFWM and related "transient grating" experiments that have been performed for application to phase conjugation and to carrier dynamics studies.
76 citations
TL;DR: In this article, a novel laser resonator with the ability to correct for intracavity phase distortions is presented, which employs a passive (self-pumped) phase conjugate reflector to provide this capability.
Abstract: We report here a novel laser resonator with the ability to correct for intracavity phase distortions. The optical cavity employs a passive (self-pumped) phase conjugate reflector to provide this capability.
72 citations
TL;DR: In this article, a summary of experiments which show how retrodirective arrays have been used to approximate phase conjugation is presented, along with a detailed discussion of the experiments and their results.
Abstract: A summary of experiments is presented which show how retrodirective arrays have been used to approximate phase conjugation.
48 citations
TL;DR: Optic observation of phase conjugation by stimulated Brillouin scattering using KrF-laser radiation (248 nm) is reported.
Abstract: We report observation of phase conjugation by stimulated Brillouin scattering using KrF-laser radiation (248 nm). The backscattered signal consists of both phase-conjugate and non-phase-conjugate components, which have different temporal behavior. This phase-conjugate Brillouin mirror has been used in a double-pass KrF laser-amplifier system, and as an element in a KrF-laser resonator, to compensate for aberrations and to produce a diffraction-limited output beam.
45 citations
TL;DR: The theory for phase conjugation in stimulated scattering is described in detail in detail as mentioned in this paper, and the basic experimental results on the conjugations are also discussed in detail, as well as the intervals of values of various parameters in which the conjogate configuration (the specklon) exists.
Abstract: 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.
44 citations
TL;DR: In this paper, it was shown that complete cancellation of distortion effects by the technique of phase conjugation can be achieved under the following circumstances: the scatterer is nonabsorbing, the conjugate wave is generated without losses or gains at an infinite phase-conjugate mirror and the effects of the evanescent waves outside the SCA are negligible.
TL;DR: Efficient, diffraction-limited, phase conjugation of an XeF (3511-A) laser beam using stimulated Brillouin scattering is reported, and approximately 70% of the 1-GHz bandwidth-locked portion of an injection-lockedXeF laser output is phase conjugal by focusing the laser beam at 5 GW/cm (2) into hexane or isopropanol.
Abstract: We report efficient, diffraction-limited, phase conjugation of an XeF (3511-A) laser beam using stimulated Brillouin scattering. Approximately 70% of the 1-GHz bandwidth-locked portion of an injection-locked XeF laser output is phase conjugated by focusing the laser beam at 5 GW/cm2 into hexane or isopropanol.
TL;DR: In this article, the use of resonantly enhanced four-wave mixing to generate high reflectivity phase-conjugate waves is discussed and a physical understanding of the mechanisms underlying the nonlinear response for a simple two-level system is presented followed by a discussion of the complicating effects of pump absorption, pump depletion, unbalanced pumps, and thermal motion.
Abstract: The use of resonantly enhanced four-wave mixing to generate high reflectivity phase-conjugate waves is discussed. A physical understanding of the mechanisms underlying the nonlinear response for a simple two-level system is presented followed by a discussion of the complicating effects of pump absorption, pump depletion, unbalanced pumps, and thermal motion. Modifications of the theory to describe four-level behavior are presented and compared with experiments. The application of nearly degenerate four-wave mixing to narrow-band filtering complicated by the A. C. Stark effect is dis-cussed along with examples of experimental observations.
TL;DR: In this paper, phase conjugation in staurable amplifiers by degenerate frequency mixing (DFM) was analyzed using numerical solutions for the appropriate equations, and the results were compared to those for saturable absorbers.
Abstract: Phase conjugation in staurable amplifiers by degenerate frequency mixing (DFM) is analyzed using numerical solutions for the appropriate equations. DFM reflectivities up to 104are predicted with pump intensities considerably less than the saturation intensity. The results are compared to those for saturable absorbers. Effects of spontaneous emission in the amplifiers are also considered.
TL;DR: In this paper, phase conjugation in stimulated backscatter of a focused aberrated beam, including the effects of pump depletion, has been investigated and shown to have a prominent axial spike closely matching that of the incident beam; however, the near field distribution had large and rapid spatial inhomogeneities.
TL;DR: In this paper, a theory relating to correction of distortions that may be achieved by phase conjugation is developed on the basis of the first Born approximation, and it is shown that, to good accuracy, the effect of a distorting medium on an incident wave is eliminated by phase-conjugation if the following conditions are satisfied: the incident field contains no evanescent components, the transmitting medium is a weak, nonabsorbing scatterer, and backscattering of the incident and of the conjugate wave and also the effects of scattered evanescence waves
Abstract: A theory relating to correction of distortions that may be achieved by phase conjugation is developed on the basis of the first Born approximation. It is shown that, to good accuracy, the effect of a distorting medium on an incident wave is eliminated by phase conjugation if the following conditions are satisfied: the incident field contains no evanescent components, the transmitting medium is a weak, nonabsorbing scatterer, and backscattering of the incident and of the conjugate wave and also the effects of scattered evanescent waves are negligible.
17 Sep 1982
TL;DR: In this article, two dimensional numerical simulations are presented of phase conjugation in stimulated backscatter of a focused abberrated beam, including the effects of pump depletion, in all cases, pump depletion significantly improved the conjugations fidelity.
Abstract: : Two dimensional numerical simulations are presented of phase conjugation in stimulated backscatter of a focused abberrated beam, including the effects of pump depletion. In all cases, pump depletion significantly improved the conjugation fidelity H. As expected, the far field distribution of light scattered back through the aberrator exhibited a prominent axial spike closely matching that of the incident beam; however, the near field distribution had large and rapid spatial inhomogeneities, even for H approximately 90%. In spite of such structure, the backscatter was able to reproduce a rough image of large scale modulation in the incident beam.
TL;DR: Using counterrotating circularly polarized waves as the pumping sources, it is demonstrated the generation of phase-conjugated vector wave fronts in the D(2) resonance line of sodium.
Abstract: Using counterrotating circularly polarized waves as the pumping sources, we have demonstrated the generation of phase-conjugated vector wave fronts in the D(2) resonance line of sodium. Experimental results that are consistent with the calculation of the third-order nonlinear susceptibility in atomic lines have been obtained.
TL;DR: In this article, an extension of a recently developed theory of cancellation of distortions by phase conjugation is presented, where the influence of backscattering of both the incident and conjugate waves is considered.
Abstract: An extension is presented of a recently developed theory (based on the first Born approximation) of cancellation of distortions by phase conjugation. The influence of backscattering of both the incident and the conjugate waves is considered. It is shown that, when backscattering is taken into account, distortions are not eliminated by phase conjugation, except when the conjugate wave is generated without a loss or a gain.
Patent•
10 Jun 1982TL;DR: In this paper, an apparatus and method of producing a phase conjugate replica of a light beam involves internal reflection of the beam within a body of mixing material which lacks inversion symmetry.
Abstract: An apparatus and method of producing a phase conjugate replica of a light beam involves internal reflection of the beam within a body of mixing material which lacks inversion symmetry. The orientation of the body relative to the incoming beam is adjusted such that at least one auxiliary beam splits off from the incoming beam, is internally reflected at least twice by the surface of the material and returns to the incoming beam within the material for scattering as an oppositely directed phase conjugate replica thereof.
TL;DR: In this article, the authors 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.
Abstract: 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.
TL;DR: In this article, unique properties of transverse and axial modes of phase-conjugate-mirror resonators are discussed and experimental results already published are summarized and compared.
Abstract: Unique properties of transverse and axial modes of phase-conjugate-mirror resonators are discussed and experimental results already published are summarized.
TL;DR: In this article, the authors discuss how conventional (static/linear) optical elements can compensate for many classes of time-varying phase distortions in optical trains, including thresholds, pumps, and frequency translations.
Abstract: We discuss how novel arrangements of conventional (static /linear) optical elements can compensate for many classes of time -varying phase distortions in optical trains. Precision corner arrays, lens arrays, and K- mirror arrays are all applicable as pseudoconjugation elements in certain classes of problems. In some cases multipassing (four or more passes) of a distorting medium can offer improved performance. Although the compensation is more limited than that available from nonlinear optical phase conjugation (NOPC), problems associated with thresholds, pumps, and frequency translations are eliminated. Abstract. We discuss how novel arrangements of conventional (static/linear) optical elements can compensate for many classes of time-varying phase distortions in optical trains. Precision corner arrays, lens arrays, and K-mirror arrays are all applicable as pseudoconjugation elements in certain classes of problems. In some cases multipassing (four or more passes) of a distorting medium can offer improved performance. Although the compensation is more limited than that available from nonlinear optical phase conjugation (NOPC), problems associated with thresholds, pumps, and frequency translations are eliminated.
TL;DR: In this article, the first observation of non-cavity optical bistability and hysteresis in phase conjugation by degenerate six-photon mixing in CdS crystals together with some analytical consideration is reported.
TL;DR: In this article, degenerate four-wave mixing and two-dimensional phase conjugation of surface plasmons at an interface between a mental and a non-linear dielectric medium is considered.
TL;DR: In this paper, the transient response of Kerr-like phase conjugators is treated and reviewed for specific cases such as pulse reshaping, chirp reversal, and temporal reversal of optical waveforms.
Abstract: The transient response of Kerr-like phase conjugators is treated and reviewed. The cases of cw and transient pump waves are considered. A general formalism is derived, with application to specific cases such as pulse reshaping, chirp reversal, and temporal reversal of optical waveforms.
01 Jan 1982
TL;DR: In this article, the authors summarized the nonlinear optical methods allowing one to perform optical phase conjugation, i.e., spatial-phase reversal of an incoming electromagnetic wave.
Abstract: This article summarizes the nonlinear optical methods allowing one to perform optical phase conjugation, i. e. spatial-phase reversal of an incoming electromagnetic wave. Special attention is given to the most powerful technique—to date—which is based on degenerate four-wave mixing (DFWM). One discusses the physical processes (one-photon and two-photon resonances) responsible for DFWM. The generation of light-induced Bragg gratings, and the analogy with real-time holography are emphasized, with a brief review of the applications in adaptive optics and imaging (wavefront rectification, etc.). Also described are the spectroscopic applications of DFWM (transient gratings, Doppler-free emission in gases, high-frequency heterodyne spectroscopy), the polarization properties of phase-conjugate mirrors, and the operation of phase-conjugate resonators.
TL;DR: The orthogonality properties of the eigenmodes of general optical resonators which have a phase conjugate mirror at one end are derived and it is shown that essentially these are biorthogonal relations as in conventional resonators.
Abstract: The orthogonality properties of the eigenmodes of general optical resonators which have a phase conjugate mirror at one end are derived. It is shown that essentially these are biorthogonal relations as in conventional resonators, which are satisfied between the set of modes propagating in one direction around the resonator and the adjoint set of modes propagating in the reversed direction.
TL;DR: The fidelity of the phase-conjugate signal produced by degenerate four-wave mixing was evaluated by conjugating and recombining the multiple-beam output from a phase grating.
Abstract: The fidelity of the phase-conjugate signal produced by degenerate four-wave mixing was evaluated by conjugating and recombining the multiple-beam output from a phase grating. A single output beam resulted. If one or more of the beams emerging from the grating were blocked, additional beams appeared whose relative amplitudes agreed with theory for a perfect phase conjugator.