Journal ArticleDOI
Beam coupling in photorefractive liquid crystal light valves
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TLDR
In this article, the beam coupling in photorefractive liquid crystal light valves (LCLVs) was studied. And the authors showed that the two-beam coupling gain can be enhanced by the Talbot effect related to multi-passage of the beams through the successive layers of the nematic liquid crystal.Abstract:
Photorefractive liquid crystal light valves (LCLVs) are hybrid devices that combine a nematic liquid crystal layer with a thin monocrystalline Bi12SiO20 (BSO) photorefractive crystal in the form of a cell wall. The device behaves as an optically addressed spatial light modulator, where the photoconductive layer is made of the BSO crystal. Differently from conventional types of spatial light modulators, usually working in retroreflective configuration, the photorefractive light valves work in transmission, thus allowing new applications related to the coupling of the optical beams when they pass through the liquid crystal layer. Here, we review some recent experiments of beam coupling in photorefractive LCLVs. After a characterization of the device in terms of its spatial resolution, which is related to the features of pattern formation in an optical feedback configuration, we present two-beam coupling and optical amplification in single pass experiments. Then, we develop a theoretical model by taking into account the Raman–Nath diffraction of the incoming beams over the thin liquid crystal layer. By using two or more light valves in cascade, we show, both experimentally and theoretically, that the two-wave mixing gain can be enhanced by the Talbot effect related to the multi-passage of the beams through the successive layers of the nematic liquid crystal. Finally, we show that self-pumped phase conjugation can be realized by placing the light valve in a tilted feedback configuration. In this case, the four-wave mixing is spontaneously created through the scattering of the signal beam onto the feedback induced grating.read more
Citations
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Non-Gaussian Statistics and Extreme Waves in a Nonlinear Optical Cavity
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Self-activating liquid crystal devices for smart laser protection
TL;DR: In this paper, a review of the up-to-date laser protection and shielding technologies is presented, focusing on self-activating liquid crystal devices that can block or attenuate the laser when the laser intensity is higher than a maximum permissible exposure value.
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Spatial solitons in liquid-crystal light valves.
TL;DR: It is demonstrated that nematicon excitation, propagation, and steering in photoconductive light valves can be demonstrated in liquid-crystal light valves.
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Transmissive liquid crystal light-valve for near-infrared applications
TL;DR: An optical valve is realized by associating a nematic liquid crystal layer with a Cr-doped gallium arsenide as a photoconductive substrate to efficiently operate in transmission at 1.06 μm optical wavelength.
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Slow light using wave mixing in liquid crystal light valve
TL;DR: In this paper, a liquid crystal light valve is used to slow down optical pulses to group velocities as slow as a few tenths of mm/s, corresponding to a very large group index.
References
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Journal ArticleDOI
Coupled wave theory for thick hologram gratings
TL;DR: In this paper, a coupled wave analysis of the Bragg diffraction of light by thick hologram gratings is given, analogous to Phariseau's treatment of acoustic gratings and to the dynamical theory of X-ray diffraction.
Journal ArticleDOI
Holographic storage in electrooptic crystals. i. steady state
TL;DR: In this paper, a non-linear theory of self-diffraction on the light induced grating of refractive index in electrooptic crystals is developed and the intensities of the diffracted beams, the diffraction efficiency, and the shape of the surfaces of equal index change are calculated analytically for saturation holograms.
Journal ArticleDOI
Self-pumped, continuous-wave phase conjugator using internal reflection
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%.
Journal ArticleDOI
Spatial solitons in photorefractive media.
TL;DR: In this article, the authors show that photorefractive media can support a new type of spatial soliton, in which the diffraction is balanced by the self-scattering (two-wave mixing) of the beam spatial frequency components.
Journal ArticleDOI
Amplified reflection, phase conjugation, and oscillation in degenerate four-wave mixing
Amnon Yariv,David M. Pepper +1 more
TL;DR: A number of new optical effects that result from degenerate four-wave mixing in transparent optical media are proposed and analyzed and are relevant to time-reversed (phase-conjugated) propagation as well as to a new mode of parametric oscillation.