Topic
Phase conjugation
About: Phase conjugation is a research topic. Over the lifetime, 3694 publications have been published within this topic receiving 49099 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: It is demonstrated that single-mode broadband amplified spontaneous parametric downconversion, combined with optical parametric amplification, can be used as a classical source of phase-sensitive cross-correlated beams and measured optical coherence tomography signals with standard InGaAs photodiodes, thus realizing the first classical interferometer based on amplified parametric fluorescence.
Abstract: We demonstrate that single-mode broadband amplified spontaneous parametric downconversion, combined with optical parametric amplification, can be used as a classical source of phase-sensitive cross-correlated beams. We first study the single spatial mode emission and the spectral brightness properties of the parametric fluorescence, produced in periodically poled MgO-doped lithium niobate. Using the same single-pass bulk-crystal configuration for a pulsed optical parametric amplifier, we achieve a gain of approximately 20 dB at an average pump power of 2W, and explain the pulse narrowing observed at the output of both parametric fluorescence and amplification in the regime of high gain. Combining these two nonlinear processes, we measured optical coherence tomography signals with standard InGaAs photodiodes, thus realizing the first classical interferometer based on amplified parametric fluorescence. The results suggest their utility for demonstrating phase-conjugate optical coherence tomography.
14 citations
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.
14 citations
TL;DR: In this paper, the solitary-wave solutions of the four-wave equations are studied and their relevance to four wave mixing in finite media is discussed, and the authors show that by controlling the linear phase mismatch judiciously, it is often possible to effect a complete transfer of action from the pump waves to the probe and signal waves.
Abstract: The solitary-wave solutions of the four-wave equations are studied, and their relevance to four-wave mixing in finite media is discussed. In general, the transfer of action from the pump waves to the probe and signal waves is limited by nonlinear phase shifts that detune the interaction. However, by controlling the linear phase mismatch judiciously, it is often possible to effect a complete transfer of action from the pump waves to the probe and signal waves.
14 citations
TL;DR: In this paper, the self-pumped phase-conjugated reflectivities in KNbO3 crystals doped with Fe have been optimized in specially cut crystals, achieving reflectivities of as high as 60%.
Abstract: Self-pumped phase-conjugated reflectivities in KNbO3 crystals doped with Fe have been optimized in specially cut crystals. Without using external cavities, we have obtained reflectivities of as high as 60%. With the pump beams derived from the self-pumped phase-conjugation process, degenerate four-wave mixing buildup time is 6 s, with a reflectivity of 30%. For the first time, the double incoherent phase conjugation in KNbO3 is also reported with reflectivities of as high as 65% and buildup times of 10 s. We present what are, to our knowledge, the first experiments on quantitative investigations of the fidelity of double phase-conjugate mirrors by interferometric methods that showed the high quality of the phase-aberration correction achieved in Fe:KNbO3.
14 citations
TL;DR: Numerical simulations and experiment show that control of the outgoing beam phase using SA phase conjugation can lead to efficient compensation of turbulence effects and results in an increase of the projected laser beam power density on a remote extended target.
Abstract: Adaptive optical systems for laser beam projection onto an extended target embedded in an optically inhomogeneous medium are considered. A new adaptive optics wavefront control technique--speckle-average (SA) phase conjugation--is introduced. In this technique mitigation of speckle effects related to laser beam scattering off the rough target surface is achieved by measuring the SA wavefront slopes of the target return wave using a conventional Shack-Hartmann wavefront sensor. For statistically representative speckle averaging we consider the generation of an incoherent light source, referred to here as a Collett-Wolf beacon, directly on the target surface using a rapid steering (scanning) auxiliary laser beam. Our numerical simulations and experiment show that control of the outgoing beam phase using SA phase conjugation can lead to efficient compensation of turbulence effects and results in an increase of the projected laser beam power density on a remote extended target. The impact of both target anisoplanatism and the Collett-Wolf beacon size on adaptive system performance is studied.
14 citations