We demonstrate a cw doubly resonant optical parametric oscillator that is frequency doubled in an external resonant cavity to the visible spectral range. We obtained single-frequency radiation in the range 565–590 nm with as much as 3.8 mW of power, which is continuously tunable over an 18-GHz range and step tunable over 160 GHz. The source is well suited for high-resolution spectroscopy in the visible region. As a demonstration, we performed persistent hyperfine spectral hole-burning spectroscopy of Eu<sup>3+</sup>: Y<sub>2</sub>SiO<sub>5</sub> . Reliable operation of the source permitted studies of the hole's lifetime over several hours.
© 2001 Optical Society of America
T. Petelski, R. S. Conroy, K. Bencheikh, J. Mlynek, and S. Schiller, "All-solid-state, tunable, single-frequency source of yellow light for high-resolution spectroscopy," Opt. Lett. 26, 1013-1015 (2001)