The gray-tracking of KTiOPO₄ nonlinear crystals, which is used for second harmonic generation of solid state lasers, have been investigated. The susceptibilities of gray-tracking were evaluated by measuring the reduction of transmittance of the crystal with the second harmonics pulse of Nd:YAG laser, and were compared with the optical absorption coefficients and contaminants in each crystal. As result, the susceptibility indicated a dependence on the initial absorption at 532-nm wavelength. Moreover, it was prevented with increasing hydroxyl concentration in the crystals. We propose a new approach toward the improvement of gray-tracking for KTP crystals annealing process under control if the humidity.

Date Published: 3 March 2000
PDF: 5 pages
Proc. SPIE 3902, Laser-Induced Damage in Optical Materials: 1999, (3 March 2000); doi: 10.1117/12.379302

Published in SPIE Proceedings Vol. 3902:
Laser-Induced Damage in Optical Materials: 1999
Gregory J. Exarhos; Arthur H. Guenther; Mark R. Kozlowski; Keith L. Lewis; M. J. Soileau, Editor(s)