Subject of study. The dynamics of photorefractive hologram formation in Cu:LiNbO 3 structures, fabricated via the thermal diffusion doping of copper ions into lithium niobate crystals, is investigated. Aim of study. The aim of this study is to synthesize Cu:LiNbO 3 samples with enhanced photovoltaic properties for practical applications. Methods. Thermal diffusion doping was performed from 800-nm-thick copper films at temperatures of 600°C and 700°C in an argon atmosphere for 12 h. The concentrations of the Cu + and Cu 2+ ions were determined by optical absorption measurements at wavelengths of 532 and 808 nm, respectively. Photorefractive holograms were recorded, and the temporal evolution of the diffraction efficiency was measured using laser beams with wavelengths of 532 and 650 nm. Main results. Thermal diffusion at 700°C results in the maximum concentrations of donor and trap centers near the X-faces of the crystal plate. The photorefractive holograms formed in these structures exhibit a diffraction efficiency of approximately 0.22 at a grating period of 10 µm (recording time: approximately 100 s). Practical significance. The obtained Cu:LiNbO 3 structures are promising for devices exploiting the evanescent fields of dynamic photorefractive holograms, including hybrid “liquid crystal/Cu:LiNbO 3 ” components and photovoltaic tweezers used for the manipulation of micro- and nano-objects.
Kolmakov et al. (Tue,) studied this question.