The Lamb dip at the center of sequence-band CO2 laser transitions is detected optogalvanically by using a low-pressure N2-CO2 discharge. The first derivative of this signal is used to frequency stabilize a sequence-band CO2 laser to a stability of better than 2 × 10-9.
© 1987 Optical Society of America
Jow-Tsong Shy and Tsu-Chiang Yen, "Optogalvanic Lamb-dip frequency stabilization of a sequence-band CO2 laser," Opt. Lett. 12, 325-327 (1987)