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: A phase conjugate mirror based on stimulated Brillouin scattering (SBS-PCM) has been applied to the Thomson scattering system in the JT-60U tokamak for the first time in order to improve the measurement performance.
Abstract: A high performance phase conjugate mirror based on stimulated Brillouin scattering (SBS-PCM) has been applied to the Thomson scattering system in the JT-60U tokamak for the first time in order to improve the measurement performance. A SBS-PCM realized a high reflectivity of 95% at a high input power of 145W (2.9J, 50Hz). Using the SBS-PCM, two methods have been developed to increase the intensity of scattered light. For the first method, we have developed a new optical design to provide a double-pass scattering method with the SBS-PCM. A laser beam passing through the plasma is reflected by the SBS-PCM. The reflected beam passes the plasma again along the same path by means of the phase conjugation of the optically nonlinear stimulated Brillouin scattering process. The double-pass Thomson scattering method using the SBS-PCM has demonstrated an increase of the scattered light by a factor of 1.6 compared with the single-pass scattering method in JT-60U. A multipass Thomson scattering method in which the las...
30 citations
••
TL;DR: Long-term storage and phase conjugation of multiple images by using a backward-stimulated echo scheme in the 3H4 -3Po transition of Pr3+:LaF3 crystal is observed.
Abstract: We have observed long-term storage and phase conjugation of multiple images by using a backward-stimulated echo scheme in the 3H4–3P0 transition of Pr3+:LaF3 crystal. The temporal order of the multiple-echo images is the reverse of that of the input images. Each of the echo images is a phase-conjugate replica of the input images and lasts as long as 15 sec. This constitutes, in principle, the first reported demonstration of an ultrafast holographic movie using a stimulated photon echo.
30 citations
••
TL;DR: In this paper, the fidelity of partially phase conjugated images is considered taking into account the finite aperture of the conjugate mirrors, and the analysis is based on the conservation of energy and the reciprocity theorems.
30 citations
••
TL;DR: In this paper, a parametric device based on four-wave mixing in fibers enables the amplification, frequency conversion and phase conjugation of optical signals, and it can be used for optical communications.
Abstract: Parametric devices based on four-wave mixing in fibers enable the amplification, frequency conversion and phase conjugation of optical signals.
30 citations
•
09 Dec 1988TL;DR: In this paper, a method for iterative phase conjugation adaptive reduction of phase aberration effects upon the time delays necessary for formation of a beam of coherent energy focused within a non-homogeneous medium at a selected range R from, and at an angle ϑ with respect to the normal to, the surface of an array of a plurality N of transducers, each for providing a portion of the energy of the beam when excited and for converting energy reflected to a signal therefrom, first bounces from a large collection of scatter-ers, contained in a portion to be investigated
Abstract: A method for iterative phase conjugation adaptive reduction of phase aberration effects upon the time delays necessary for formation of a beam of coherent energy focused within non-homogeneous medium at a selected range R from, and at an angle ϑ with respect to the normal to, the surface of an array of a plurality N of transducers, each for providing a portion of the energy of the beam when excited and for converting energy reflected thereto to a signal therefrom, first bounces from a large collection of scatterers, contained in a portion of the medium to be investigated, a probe beam for that beam angle ϑ. The received signals from each of the (N-1) pairs of adjacent transducers are cross-correlated to derive a like number of phase conjugation correction signals, which are then arithmetically operated upon to provide a time correction for the time delay associated with each probe beam transducer, for that range R and angle ϑ. The time correction for each transducer then modifies each of at least one iteration of excitation to, and return signal received from, the media portion. A plurality of iterations, with each excitation made with the most recent corrected delays values, better focuses the interrogating beam, until, after a selected number of iterations, actual imaging data can be obtained with minimal phase aberrations.
30 citations