Type II quasi-phase matching was employed for first-order frequency doubling of a single-longitudinal-mode Ti:sapphire laser in periodically poled KTP with a domain-inverted period of 9.01 μm . In a single-pass configuration, 0.44 mW of UV power at 398.8 nm was generated for an input of 780 mW, corresponding to a normalized conversion efficiency of 0.09%W<sup>-1</sup> cm<sup>-1</sup> . The nonlinear coefficient d<sub>24</sub> = 2.82 pm/V was deduced from the measurements. The larger grating period for the type II quasi-phase-matched second-harmonic-generation process than for type I quasi-phase matching, lowers the fabrication constrains in the short-wavelength region and increases the acceptance bandwidth.
© 1999 Optical Society of America
S. Wang, V. Pasiskevicius, J. HellstrÃ¶m, F. Laurell, and H. Karlsson, "First-order type II quasi-phase-matched UV generation in periodically poled KTP," Opt. Lett. 24, 978-980 (1999)