Abstract

The colour centres responsible for the additional laser-induced absorption (“gray tracking") appear in KTP crystals under the action of the blue-green laser radiation. This effect significantly limits the application of KTP frequency doublers. The value of the nonlinear absorption depends on the incident radiation intensity, exposure (number of shots), and mutual orientation of the plane of polarization of the laser radiation E and the polar axis Z of the KTP crystal.¹

© 1994 IEEE