Ultraviolet writing of channel waveguides in proton-exchanged LiNbO₃

We report on a direct ultraviolet (UV) writing method for the fabrication of channel waveguides at 1.55 µm in LiNbO3 through UV irradiation of surface and buried planar waveguides made by annealed proton exchange and reverse proton exchange. A systematic study of the guidance properties as a function of the UV writing conditions is presented

Laser-induced pyroelectric competitive contributions to the optical damage in LiNbO3 crystals

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Z-scan study of nonlinear absorption in reduced LiNbO3 crystals

International audienceThe nonlinear absorption (NLA) was studied by open-aperture Z-scan experiments in the chemically reduced nominally pure LiNbO3 crystals at cw-illumination with the red (644 nm) and green (514.5 nm) laser beams. The magnitude of the measured NLA is considerably different from the reported Z-scan results obtained in as-grown LiNbO3. The positive sign of NLA obtained with the red light has been related to the generation of the small bound polarons absorbing in red and near-IR ranges. Application of green light results in the light-induced transparency, i.e., the Z-scan traces show negative sign of NLA. Intensity dependence of Z-scan traces allows for conclusion that the photo-induced dissociation of small NbLi 4þ:NbNb4þ bipolarons and sequent generation of small polarons gives the dominating contribution to the nonlinear optical absorption in reduced crystals with a large bipolarons concentration

Optical damage in chemically reduced LiNbO3 crystals

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Optical damage dynamics in reduced nominally pure LiNbO3 crystals

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Investigation of nonlinear refraction and absorption in Mg- and Zr-doped LiNbO3 with the aid of Z-scan techniques

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Kinetics of photorefractive response in reduced nominally pure liNbO3 crystals

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