Results 121 to 130 of about 533 (174)

Photorefractive effect in GaP

Optics Letters, 1990
The photorefractive effect in undoped semi-insulating GaP was observed. GaP has a photorefractive sensitivity in the spectral region of 0.6 to 0.9 microm. The photorefractive center is the deep donor resulting from the P antisite defect. We measured the two-beam coupling gain coefficient and its time constant as functions of the grating period and the ...
K, Kuroda, Y, Okazaki, T, Shimura, H, Okamura, M, Chihara, M, Itoh, I, Ogura   +6 more
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Optics for photorefractive keratectomy

Journal of Cataract and Refractive Surgery, 1993
Matrix calculations are applied to Gaussian optics in the study of myopic correction by photorefractive keratectomy. The Colliac matrix formula determines the postoperative anterior curvature radius of the treated cornea. It also calculates the maximal depth of the removed corneal tissue and the ablation zone diameter needed to achieve emmetropia.
J P, Colliac, H J, Shammas
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Photorefractive integrator characterization

Applied Optics, 1995
We describe the recent results of our efforts to characterize a photorefractive crystal to be used as a time-integrating device in an optically implemented null-steering adaptive processor for phased-array radar. We review frequency response data for the Bi(12)SiO(20) crystals, measured with an acousto-optic apparatus, and we present measured dynamic ...
J H, Hong, J B, Norman, T Y, Chang, F, Vachss, D C, Pletcher   +4 more
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Enhanced photorefractive performance in a photorefractive polymeric composite

Journal of Applied Physics, 1994
We characterize the photorefractive behavior of a photorefractive multicomponent polymer composite of PVK-TCP:C60:DEANST. Efficient plasticization of the host polymeric matrix and utilization of a nonlinear chromophore with a large dipole moment provide a large poling-induced electro-optic coefficient.
Maciek E. Orczyk, Bogdan Swedek, Jaroslaw Zieba, Paras N. Prasad   +3 more
openaire   +1 more source

Photorefractive four wave mixing and photorefractive circuits

Nonlinear Optics: Materials, Fundamentals, and Applications, 1992
Degenerate four wave mixing in photorefractive media(PFWM) has been intensively studied theoretically. A complete solution of the coupled wave equation is steel not available. This makes some problems such as the uncertainty of the solution, lack of understanding of phase dependence and energy flux, and unable to treat those of multi coupled ...
S.L. Wang, H.F. Pan
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Photorefractive keratectomy in children

Journal of Cataract and Refractive Surgery, 2002
To evaluate photorefractive keratectomy (PRK) in pediatric patients who fail traditional methods of treatment for myopic anisometropic amblyopia and high myopia.Nonhospital surgical facility with follow-up in a hospital clinic setting.Photorefractive keratectomy was performed in 40 eyes of 27 patients.
William F, Astle, Peter T, Huang, Anna L, Ells, Robin G, Cox, Micheline C, Deschenes, Heather M, Vibert   +5 more
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Photorefractive polymer materials

SPIE Proceedings, 1993
Photorefractivity, or reversible photoinduced refractive index change, was first observed about twenty-five years ago in inorganic crystals. The photorefractive effect involves generation, transport and trapping of charges and a change of the refractive index through the electro-optic effect.
BOLINK, HJ, KRASNIKOV, VV, MALLIARAS, GG, HADZIIOANNOU, G   +3 more
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Photorefractive flip-flop

Optics Letters, 1991
We demonstrate an optical flip-flop that consists of two unidirectional ring resonators that are coupled competitively through two-beam interactions in a photorefractive BaTiO(3) crystal. This crystal provides an active loss for each ring that depends on the oscillation intensity of the other.
D Z, Anderson, C, Benkert, B, Chorbajian, A, Hermanns   +3 more
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Photorefractive surface waves

Optics Letters, 1995
A laser beam propagating in a photorefractive crystal generates a refractive-index profile that deflects the beam to one side. This nonlinear deflection can be balanced by total internal reflection at the crystal surface to produce self-induced photorefractive surface waves. Theoretical and experimental evidence for this effect is given.
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Photorefractive Dynamic Optical Interconnects

SPIE Proceedings, 1988
We present and demonstrate a set of dynamic optical interconnects which are based on the double phase conjugate mirror with photorefractive wave mixing. These devices are bidirectional, self-adjusting, and controllable in real time. Uses in various interconnection modes are given.
S, Weiss, M, Segev, S, Sternklar, B, Fischer   +3 more
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