SUB-DOPPLER FREQUENCY MEASUREMENTS ON OCS NEAR 1689 AND 1885 CM(-1)

We have used an optical polarization heterodyne technique to measure the frequencies of two OCS lines, one near 5.3 mu m and the other near 5.9 mu m. These sub-Doppler measurements gave 56 533 766.125 +/- 0.035 MHz for the 2 nu(2) + nu(3) P(16) transition and 50 627 632.013 +/- 0.100 MHz for the 283 P(48) line. The P(16) measurement is in excellent agreement (20 kHz) with a new result obtained with an alternate technique by a group at the University of Bonn. The 2 nu(3) measurement was combined with other frequency measurements to produce an improved calibration table for the 283 OCS band near 1700 cm(-1). These and other sub-Doppler frequency measurements in different spectral regions give improved frequencies for a number of OCS bands. These new frequencies will soon be incorporated into calibration data that will be available over the Internet. (C) 1995 Academic Press, Inc.