Multiphoton absorption and luminescence of chromyl chloride

Abstract

Infrared multiphoton absorption (MPA) of chromyl chloride (CrO 2Cl 2) and luminescence, due to inverse electronic relaxation (IER), were studied in the gas phase at pressures of 6.7 to 133 Pa (0.050 to 1.00 Torr) with CO 2 laser pulses of 10 and 60 ns duration. A dependence of MPA measured photoacoustically, on pulse length, was observed at 6.7 Pa but not at 67 Pa, with a factor of 2.5 greater absorption for the shorter laser pulse at the lower pressure. A much larger dependence of luminescence intensity on laser pulse duration was observed at 6.7 Pa with a factor of 10 to 40 increase in luminescence signal for the shorter laser pulse. The origin of the intensity dependences in the MPA and luminescence experiments is discussed and it is shown that the two dependences are not completely related.