Lithium niobate (LiNbO3, LN) devices play critical roles in quantum information processing. However, for special applications like key distribution (QKD), the characteristics of materials and their impact on practical systems must be intensively inquired. For first time, we reveal that photorefractive effect LN can utilized as a potential loophole to carry out malicious attacks by eavesdroppers...

Green-induced infrared absorption ~GRIIRA! was investigated by a photothermal technique for undoped and Mg-doped LiNbO3 crystals that have different Li/Nb ratios. Threshold effect on GRIIRA was found, threshold MgO concentrations being the same for GRIIRA and photorefraction. We suggest that GRIIRA is associated with the formation of the small polaron that is located on Nb antisite defect. The ...

Permanent grating patterns have been written directly in lead-tin-fluorophosphate glasses by use of UV radiation. The effect of photorefraction is studied in different tin-fluorophosphate compositions. Recorded gratings are found to be volume rather than surface elements. The induced index changes are comparable with those seen in GeO(2)- SiO(2) glasses.

We try to improve the accuracy of eccentric photorefraction by taking more information into account than just the size and tilt of the crescent. Based on Gaussian optics and the assumption of an isotropic scattering retina, a theoretical analysis of the light-intensity distribution in the pupils of astigmatic eyes is presented. The method is applied to different photorefractor setups (point lig...

We report intracavity Bragg scattering induced by the photorefractive (PR) effect in high- Q lithium niobate ring resonators at cryogenic temperatures. show that when a cavity mode is strongly excited, PR imprints long-lived periodic space-charge field. This residual field turn creates refrac...