Elimination of Gray Tracking Effects of KTiOPO4 Crystals Using a Strong Focusin

A simple method is presented to eliminate gray-tracking effects of KTP crystals using a strong focusing scheme. Experimental and theoretical studies on the gray-tracking effects are carried out. A 18W green laser is demonstrated with a 9 kHz repetition rate, a beam quality factor of M-2 = 1.6 and a