Topic
Organic photorefractive materials
About: Organic photorefractive materials is a research topic. Over the lifetime, 697 publications have been published within this topic receiving 13041 citations.
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TL;DR: In this paper, the influence of different oxidizing and reducing treatments on the photorefractive properties of tetragonal KTa1-xNbxO3:Fe crystals is investigated.
Abstract: The influence of different oxidizing and reducing treatments on the photorefractive properties of tetragonal KTa1-xNbxO3:Fe crystals is investigated. Elementary holograms are recorded and photoconductivity, saturation value of refractive index change and gain factor are determined. The experimental results are interpreted by a model which assumes one kind of photorefractive centers with both, electrons and holes as free charge carriers, taking into account space charge limitations. We find that oxidizing treatments increase the hole contribution to photoconductivity and the effective density of photorefractive centers.
8 citations
8 citations
TL;DR: In this article, the photorefractive properties of proton-exchanged LiTaO3 waveguides are improved by the additional copper exchange, and it is established that the holographic efficiency depends on the copper content, the phase of the proton exchanged layer and the light intensity.
Abstract: are fabricated by both a proton exchange and a successive copper exchange. The influence of different fabrication steps on the refractive index profile and optical absorption is investigated. The holographic efficiency is determined together with the dark- and photo-conductivity. We show that the photorefractive properties of proton-exchanged LiTaO3 waveguides are considerably improved by the additional copper exchange. It is established that the holographic efficiency depends on the copper content, the phase of the proton-exchanged layer and the light intensity.
8 citations
TL;DR: In this paper, the gain factor for counter-propagating two-beam coupling was measured at both wavelengths for CdTe:Ge at λ = 1.064 μm and λ=1.55 μm.
Abstract: Recording of efficient reflection holograms is achieved in CdTe:Ge at λ=1.064 μm and λ=1.55 μm. The gain factor measured at both wavelengths for counterpropagating two-beam coupling considerably exceeds the absorption constant and transcends all values previously reported for semiconductors with no external field. The dependences of the gain factor on intensity and grating spacing are studied. Some crystal characteristics are estimated in the frame of a single band, one mobile species approximation of space-charge formation. The homogeneity of photorefractive properties in the crystal volume is demonstrated.
8 citations
TL;DR: In this article, a novel method of modifying photorefractive waveguides in a lithium niobate crystal by a guided beam was investigated experimentally and numerically, and it was shown that the transmitted power or peak intensity of the probe beam decreases exponentially as a function of total exposure energy of the modification beam.
Abstract: We investigate experimentally and numerically a novel method of modifying photorefractive waveguides in a lithium niobate crystal by a guided beam. The guided beam with a strong optical power can change the refractive index of the photorefractive waveguide because of the photorefractive effect. The modification of waveguide structure can be utilized for optical dynamic interconnection. Changes of optical characteristics of a probe beam caused by a modification beam are investigated. Experimental results show that the transmitted power or the peak intensity of the probe beam decreases exponentially as a function of total exposure energy of the modification beam. We also numerically analyze the refractive index change caused by the modification beam in the photorefractive waveguide. The numerical results show good agreement with the experimental results.
8 citations