HETERODYNE FREQUENCY MEASUREMENTS WITH A TUNABLE DIODE LASER - CO2 LASER SPECTROMETER - SPECTROSCOPIC REFERENCE FREQUENCIES IN THE 9.5-MU-M BAND OF CARBONYL SULFIDE

The frequencies of twelve carbonyl sulfide absorption lines near 9.5 μm have been measured by means of a heterodyne frequency measuring technique, which uses a frequency stabilized CO2 laser and a tunable diode laser.The diode laser was locked to the peak of each OCS absorption line by means of a first derivative frequency lock procedure.In addition to lines in the 0200–0000 band, measurements also include some nearby OCS hot band features as well as lines in isotopically enriched samples of OC34S, O13CS, and 18OCS.These measurements are part of an effort to provide frequency standards for the calibration of tunable IR laser devices.© 1979 Optical Society of America.