Abstract

Using noncritically phase-matched $1‐{\mathrm{cm}}^2$-aperture ${\mathrm{KTiOAsO}}_4$ (KTA) crystals in an optical parametric oscillator (OPO), we have demonstrated a sustained average signal power of 33 W at 1534.7 nm. To our knowledge, this is the highest-average-power signal ever generated by an OPO. The pump source was a 100-Hz $Q$-switched 1064-nm Nd:YAG laser. Compared with that of the similar and more-common material ${\mathrm{KTiOPO}}_4$, idler absorption in KTA is negligible, allowing high-power operation with minimal thermally induced refractive distortion in the OPO crystal.

© 1998 Optical Society of America