Influence of intrinsic defects on light-induced changes in the refractive index of lithium niobate crystals

Application of Z-scan technique for the study of nonlinear absorption in chemically reduced LiNbO3crystals

“…These β values are much smaller than the previously reported values (β = 2.7 cm/kW was evaluated [10] at λ = 532 nm and β = 5 cm/kW was evaluated [9] at λ = 514.5 nm) obtained with cw-laser beams for the undoped as-grown lithium niobate crystals. This difference can be attributed to the significant influence of the photorefractive effect on NLA measurements, as the photorefractive effect depends strongly on many uncontrollable crystal parameters and specific excitation conditions [7,12]. In the reduced crystals the light-induced absorption changes Δα have been found to be proportional to the square root of I 0 within the quite low-intensity range, Tables 1 and 2.…”

Fast photorefractive response in LiNbO3 crystal co-doped with Fe/Sm ions

“…It was well known that when the photorefractive crystals were irradiated by continuous wave laser, the photorefractive response time τ could be expressed as [7] …”

Comparative Study of Composition Dependences of Photorefractive and Related Effects in LiNbO3and LiTaO3Crystals

“…The intensity distributions (shape and the magnitude) at the focus and at a long distance after crystal were recorded with the aid of a photodiode array. It is known [15] in fact, that such investigation allows measuring the photorefraction with reliable precision.…”