Vibrational Overtone Transitions of OCS in the Near Infrared

Overtone Transitions of12CO2beyond the Venus Bands

“…The Hamiltonian for each Fermi polyad in CO 2 is much simpler than that for OCS (9). Calculations of the band origins were carried out by employing the molecular parameters taken from the work of Courtoy (11).…”

“…The sample in the cell was then aged for 2-3 days for the P 2 O 5 to reduce water vapor in the gas phase. Other conditions and experimental components were the same as those previously reported (9) except that the new cell filled with CO 2 required a resonance frequency of about 665 Hz for the mechanical chopper.…”

“…The laser system is the same as that described in our previous work (9). Briefly, a broadband Ti:Sapphire ring laser (Coherent 899-01) was pumped by a multiline Ar ϩ laser (Coherent 70-5).…”

“…The positions of the even weaker pentad were determined by using the head positions of the 1 ϩ 5 3 dyad of 13 CO 2 (12), since the high reflector had to be used to record the pentad transitions which made the output laser power too weak for recording the water transitions. Band origins were determined by rotational structure simulations as in our previous study (9). The rotational constants used for simulations were calculated according to Herzberg and Herzberg (3).…”

“…In our previous studies (8,9), it was demonstrated that overtone and combination transitions of CO 2 , N 2 O, and OCS in the near infrared can be detected directly by employing laser photoacoustic techniques with sample sizes of about several milliliters under a pressure of 1 atm. However, due to the limited spectral range of the Ti:Sapphire laser system and water interference, only the 1 ϩ 5 3 dyad of the Venus bands was detected (8).…”