Carbon dioxide laser stabilization by optoacoustic tracking of an SF6 Lamb dip

A rugged optoacoustic room temperature detection scheme is used to lock the frequency of the CO2 laser oscillating on the P(16) transition line of the 10.6-micron band to one of many potentially usable SF6 Lamb dips. A low- and high-pressure SF6 optoacoustic cells combination provides 100 percent increase in the contrast of the Lamb dip that is furthermore independent from the particular laser power gain profile. The resultant preliminary frequency stability achieved was 1 part in one hundred thousand over a 10-min period.