The frequency-doubling efficiency of a Nd:YAG laser was increased by using a variable-reflectivity-mirror unstable resonator. At 5 Hz as much as 385 mJ of green light was obtained with an efficiency of 61%. The divergence of the converted light, which was 0.26 mrad at 0.5 Hz, close to the diffraction limit, increased to 0.69 mrad at 5 Hz.
© 1989 Optical Society of America
Original Manuscript: September 26, 1988
Manuscript Accepted: January 27, 1989
Published: April 15, 1989
A. Parent and P. Lavigne, "Increased frequency conversion of Nd:YAG laser radiation with a variable-reflectivity mirror," Opt. Lett. 14, 399-401 (1989)