Ultraviolet generation in periodically poled KTiOPO/sub 4/

Quasi-phase-matching (QPM) in periodically poled ferroelectrics is a way to obtain efficient walk-off-free frequency conversion at a desired wavelength with reduced photorefractive sensitivity. First-order QPM second-harmonic generation (SHG) to the ultraviolet (UV) require fine pitch gratings. It is shown that KTP would be advantageous in high-power applications because the photorefractive sensitivity is lower for this material and the one-dimensional crystal structure makes it is easier to pole samples of mm thickness.