Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Acta Physica Sinica (Overseas Edition)

Theoretical study of the intensity dependence of total effective trap density in photorefractive crystals

Chi Ming-jun, Shuo‐Xing Dou, Peixian Ye

Published Sep 1, 1999• 0 citations
Publisher

Abstract

Intensity dependence of the total effective trap density N eff is studied theoretically for the two-centre and the three-charge-state photorefractive crystals. The results show that N eff always increases with increasing intensity in three-charge-state crystals, whereas it has more complicated behaviors in two-centre crystals. When S D γ T / S T γ D is small, N eff increases and tends to saturate with increasing intensity for both type-A and type-B two-centre crystals. When S D γ T / S T γ D is large, N eff increases to a maximum and then decreases a little for type-A crystals and decreases greatly for type-B crystals. The different intensity dependences of N eff in the two types of crystals come from their different level structures.

DOI
10.1088/1004-423x/8/9/005

Related papers

Theoretical study of the intensity dependence of two-beam coupling gain coefficient in photorefractive crystals

Jinsong Liu

Intensity dependence of the two-beam coupling gain coefficient Γ, the effective trap density N eff and the intensity dependent factor η(I) is studied theoretically for the two-centre photorefractive crystals. The results show that N eff, η(I) and Γ have more complicated behaviors in two-centre crystals. When S Dγ T/S Tγ D is small, N eff increases and tends to saturate with increasing intensity for both type-A and type-B two-centre crystals. When S Dγ T/S Tγ D is large, N eff increases to a maximum and then decreases a little for type-A crystals and decreases greatly for type-B crystals.The different intensity dependence of Γ in the two types of crystals comes from their different level structures.

Optics and Precision Engineering•Jan 1, 2001•0 citations

Intensity dependence of stationary energy transfer in codirectional photorefractive cross-polarization two-wave mixing

Jinsong Liu, Changhong Liang

The intensity dependence of stationary energy transfer in photorefractive codirectional cross-polarization two-wave mixing is examined. The intensity formulae remained effect both in the saturation and the intermediate regime (before saturation) are driven, and the analytical expressions with the ratio of saturation intensity to total incident intensity as their explicit variable are obtained for the case of pump depletion. It is necessary to use these formulae in some problems, such as the temperature or intensity dependence of cross-polarization two-wave mixing. A method of measuring the coupling coefficient and saturation intensity of a cubic photorefractive crystal is presented, which is suitable for cross-polarization two-wave mixing in the intermediate regime.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Sep 30, 1996•0 citations

Comparison of three wave mixing in photorefractive and nematic liquid crystals

David John Webb, LASZLO SOLYMAR

Consideration of the coupled wave equations governing three wave mixing in photorefractives and nematic liquid crystals, when both are exhibiting a local response, shows that the main difference between the two is the self phase modulation that occurs in the liquid crystals. It is this difference that explains the dissimilar variation of the exponential gain factor, as a function of inter-beam angle. The other difference between the two media is the dependence of gain on the total incident intensity for the case of nematic liquid crystals and on the detuning frequency for the case of photorefractive media. >

•Sep 16, 1991•0 citations

Optical bistability by photorefractive two-wave mixing

Jianquan Yao, J. Wang

It is known that two-wave coupling in photorefractive crystal may result in an intensity-dependent phase shift as well as energy transfer between the two waves without phase crosstalk. In a sense, this kind of phase shift is similar to the intensity-dependent refractive-index effects in Kerr media. Consequently, optical bistability can be established in an optical cavity with a photorefractive crystal. We formulate the model and get the expected bistable transmission with numerical simulations. Several cases, including that of the codirectional coupling and the contradirectional coupling, are considered. The effects of the photorefractive crystal’s distribution absorption and the spatial phase shift between the index grating and the light interference pattern in the crystal on the nonlinear transmission characteristics have also been studied. It is interesting to note that the output of the pumping wave is dependent on the cavity intensity and thus shows bistable behavior with respect to the cavity input as well.

Annual Meeting Optical Society of America•Jan 1, 1987•0 citations

Coherent optical gain of multistage two-wave mixing in photorefractive crystals

Jinsong Liu, Jianyong Xiang, Keqing Lu

We derive the intensity and phase formulas of the two-, three-, and n-stage codirectional parallel-polarization degenerate two-wave mixing in photorefractive media. These formulas are valid for both the saturation and intermediate regime and can be used in investigating the problem of increasing the coherent optical gain by the multistage two- wave mixing technique.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Aug 17, 1998•0 citations

Conjugation fidelity and reflectivity in photorefractive double phase-conjugate mirrors

Sergei S. Orlov, George C. Valley, Mordechai Segev +1 more

We present an experimental study of the behavior of photorefractive double phase-conjugate mirrors that illustrates recent theoretical predictions. We observe a sharp fidelity threshold that significantly depends on the specific feature size in the input beams. Furthermore, we find that if the two input beams have unequal intensities the conjugation process is asymmetric and the steady-state fidelity is better on the side of the crystal on which the more-intense beam enters.

Optics Letters•Apr 15, 1994•21 citations
Intensity dependence of the total effective trap density N eff is studied theoretically for the two-centre and the three-charge-state photorefractive crystals. The results show that N eff always increases with increasing intensity in three-charge-state crystals, whereas it has more complicated behaviors in two-centre crystals. When S D γ T / S T γ D is small, N eff increases and tends to saturate with increasing intensity for both type-A and type-B two-centre crystals. When S D γ T / S T γ D is large, N eff increases to a maximum and then decreases a little for type-A crystals and decreases greatly for type-B crystals. The different intensity dependences of N eff in the two types of crystals come from their different level structures.
Intensity dependence of the two-beam coupling gain coefficient Γ, the effective trap density N eff and the intensity dependent factor η(I) is studied theoretically for the two-centre photorefractive crystals. The results show that N eff, η(I) and Γ have more complicated behaviors in two-centre crystals. When S Dγ T/S Tγ D is small, N eff increases and tends to saturate with increasing intensity for both type-A and type-B two-centre crystals. When S Dγ T/S Tγ D is large, N eff increases to a maximum and then decreases a little for type-A crystals and decreases greatly for type-B crystals.The different intensity dependence of Γ in the two types of crystals comes from their different level structures.
The intensity dependence of stationary energy transfer in photorefractive codirectional cross-polarization two-wave mixing is examined. The intensity formulae remained effect both in the saturation and the intermediate regime (before saturation) are driven, and the analytical expressions with the ratio of saturation intensity to total incident intensity as their explicit variable are obtained for the case of pump depletion. It is necessary to use these formulae in some problems, such as the temperature or intensity dependence of cross-polarization two-wave mixing. A method of measuring the coupling coefficient and saturation intensity of a cubic photorefractive crystal is presented, which is suitable for cross-polarization two-wave mixing in the intermediate regime.
Consideration of the coupled wave equations governing three wave mixing in photorefractives and nematic liquid crystals, when both are exhibiting a local response, shows that the main difference between the two is the self phase modulation that occurs in the liquid crystals. It is this difference that explains the dissimilar variation of the exponential gain factor, as a function of inter-beam angle. The other difference between the two media is the dependence of gain on the total incident intensity for the case of nematic liquid crystals and on the detuning frequency for the case of photorefractive media. >
It is known that two-wave coupling in photorefractive crystal may result in an intensity-dependent phase shift as well as energy transfer between the two waves without phase crosstalk. In a sense, this kind of phase shift is similar to the intensity-dependent refractive-index effects in Kerr media. Consequently, optical bistability can be established in an optical cavity with a photorefractive crystal. We formulate the model and get the expected bistable transmission with numerical simulations. Several cases, including that of the codirectional coupling and the contradirectional coupling, are considered. The effects of the photorefractive crystal’s distribution absorption and the spatial phase shift between the index grating and the light interference pattern in the crystal on the nonlinear transmission characteristics have also been studied. It is interesting to note that the output of the pumping wave is dependent on the cavity intensity and thus shows bistable behavior with respect to the cavity input as well.