The 90 degrees phase-matching SHG is performed for microsecond single pulse
s from a Nd3+ :YAP laser in a KTP crystal with the 29% conversion efficienc
y. The 90 degrees phase-matching temperature is 54 degreesC. The crystal su
rface damage threshold measured without and with an antireflection coating
was 107 +/- 11 and 40 +/- 4 J cm(-2), respectively.