Sum-frequency generation utilizing two cw single-mode Nd:YAG lasers and a congruent lithium niobate crystal yielded 3.4 mW of very narrow-band (10 kHz over 1 ms) tunable 589-nm cw radiation. This simple solid-state light source is well suited for high-resolution spectroscopy of the sodium D2 line, as was demonstrated with both conventional and FM-modulated saturation spectroscopy.
© 1997 Optical Society of America
H. Moosmüller and J. D. Vance, "Sum-frequency generation of continuous-wave sodium D2 resonance radiation," Opt. Lett. 22, 1135-1137 (1997)