Phase conjugation

About: Phase conjugation is a research topic. Over the lifetime, 3694 publications have been published within this topic receiving 49099 citations.

Testing of refractive silicon microlenses by use of a lateral shearing interferometer in transmission.

Abstract: Wave aberrations of refractive photoresist microlenses and silicon microlenses were measured with a lateral shearing interferometer. Because of the silicon elements, a near-infrared working wavelength (λ = 1.32 μm) was used. The wave front was evaluated by a phase step technique with four steps. Integration of the phase distributions was performed with a computationally efficient Fourier transformation algorithm. The influence of the detector vidicon nonlinearity on the measured wave front was calculated. The defocusing behavior of the interferometer was investigated by fitting the measured wave fronts with the help of Zernike circle polynomials. It is shown that the reproducibility can be kept below λ/100 rms. Examples for the measured wave fronts of plano–convex silicon microlenses are discussed in detail.

Degenerate-four-wave mixing as a Sturm-Liouville problem.

Abstract: The problem of steady-state degenerate holographic four-wave mixing in transmission geometry in nonlinear dynamic media is reduced to a Sturm-Liouville or a one-dimensional quantum-mechanical scattering problem, which is treated exactly. Linear absorption in the medium is accounted for, and pump depletion is allowed. No restrictions are placed on the spatial phase mismatch between light-interference fringes and refractive-index gratings. Energy and phase transfer are considered simultaneously.

Theory of optical ray retracing in laser-plasma backscatter

Abstract: It is suggested that the optical ray-retracing effects observed in laser-produced plasmas originate from the same mechanism believed to cause phase conjugation from backward stimulated processes in liquids. This mechanism is elucidated with the aid of a simple model, and generalized to include plasma inhomogeneity. A comparison is made with a recent experiment.

Phase regeneration of phase encoded signals by hybrid optical phase squeezer

Abstract: We present a new method to perform phase regeneration of phase encoded signals. In our concept called "hybrid optical phase squeezer (HOPS)," a multilevel phase-quantized signal is synthesized through the coherent addition of a phase-conjugate copy of the signal and a phase harmonic of the signal with a frequency shifter. Unlike the conventional method by phase sensitive amplification, HOPS does not use any optical parametric gain such that only optical elements with low optical nonlinearity are necessary for optical phase quantization. In the proof-of-concept experiment, it is confirmed that a 2-level HOPS can perform quadrature squeezing with an extinction ratio of 40 dB. Simultaneous phase regeneration of two coherent wavelength-division-multiplexed 10.75-Gb/s binary phase-shift keyed signals is successfully demonstrated using a 2-level HOPS based on a semiconductor optical amplifier.