UV-induced nonlinear absorption in lanthanum calcium borate single crystals.
It has been revealed that lanthanum calcium borate (La2CaB10O19) crystals show two-photon absorption (TPA) induced by a UV laser field. UV-induced TPA measurements were performed in the spectral range of 475-1130 nm using as fundamental beam the third harmonics of the 28 ps Nd-YAG pulsed laser as a pumping beam for LiB3O5 optical parametrized generator using Z-scan method. Investigations performed by the Z-scan method were done during illumination by a Xe-F laser (lambda = 217 nm) as a photoinducing (pumping) beam. The pumping laser beam created a thin surface layer (about 80-90 nm) that was the source of the observed photoinduced TPA. The highest values of the TPA beta coefficients were achieved for polarization of the pumping light directed along the second-order crystallographic axis of the investigated crystals. The obtained values of the TPA coefficients were higher than those for the BiB3O6 crystals investigated earlier by us.
Kityk
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IV
Institute of Physics, J. Dlugosz Academy of Czestochowa, Al. Armii Krajowej 13/15, Czestochowa, Poland. i.kityk@ajd.czest.pl
Majchrowski
A
A
Michalski
E
E
Kasprowicz
D
D
Drozdowski
M
M
Kisielewski
J
J
Lukasiewicz
T
T
Sahraoui
B
B