Type III sum frequency generation in flux and hydrothermally grown KTP at 1.319 and 1.338 microns.

Type II noncritically phase matched sum frequency generation by mixing of the 1.319micron and 1.338micron lines of a Q-switched Nd: YAG laser with their second harmonics is demonstrated. Results are presented for crystals grown by the hydrothermal and the flux technique. A temperature acceptance width-length product of 8.5 +- 0.5C cm was determined. Type II critical phase matching at 300K, for the three different propagation/polarization orientations, is also demonstrated. The differences in the angles required for phase matching between crystals grown by the different techniques are quantified.