Photorefraction in the ultraviolet: Materials and effects

Characteristic features of ultraviolet photorefraction in iron-dopedα−LiIO3at low temperatures

“…Ultraviolet photorefraction was first studied at room temperature by Laeri et al 6 using an ␣-LiIO 3 sample doped with 34 ppm ͑mol͒ of iron. Here we investigate the lowtemperature behavior of the same sample cut with dimensions 5.8ϫ5.3ϫ4.3 mm 3 along the a,b,c crystallographic axes.…”

Pulsed UV image amplification for programmable laser marking

“…Previous work has shown that Mg doped LiNbO3 crystals are well suited for amplification in the UV using the photorefractive effect 2, 3 We used a 7.5 % mol Mg doped crystal of 10 mm thickness prepared by Nankai University. The signal beam size within the crystal was about 4 mm and the pump beam one around 6 mm in order to optimise the interaction length in the crystal.…”

Improvement of sensitivity and refractive-index changes in LiNbO3:Ce:Cu crystals with UV light

“…It has been reported in many studies that holes are the dominant charge carriers in the UV region in nominally undoped or singly doped LN crystals, especially in strongly oxidized crystals with 351 nm light, based on large gain values of the beams and the direction of the energy transfer [16][17][18]. However, in our experiments on holographic recording in doubly doped LN:Ce:Cu crystals with 364 nm UV light, electrons are confirmed to be the dominant charge carriers because no steady-state energy transfer from one recording beam to the other is observed, although the detailed origin of the difference between the singly doped and the doubly doped LN crystals influencing UV photorefraction is not clear.…”