Efficient generation of a CW 593.5-nm laser by intracavity sum-frequency mixing with a BiB3O6 (BIBO) crystal

A compact, efficient yellow-orange light at 593.5 nm was realized by the intracavity sum-frequency mixing using a BIBO crystal in a diode-pumped Nd:YVO₄ laser. At an incident pump power of 3.5 W, up to 126 mW of CW output light at 593.5 nm was achieved with a 1.5-mm-long critical phase-matching BIBO. The optical-to-optical conversion efficiency was up to 3.6%, which was comparable to a 5-mm-long LBO. The beam equality was excellent with an ellipticity of 0.97 and output noise of less than 0.8% (rms). Results confirm that the BIBO is an efficient material for frequency conversion in the visible region.