Saturation in the absorption of infrared radiation by gas molecules

T. K. Lim, George F. Caudle, Jerald R. Izatt

A O Markano, Viktor T Platonenko

The saturation of light absorption in a molecular gas is analyzed theoretically allowing for the redistribution of the molecules in terms of the orientations of their moments. It is shown that the amount of energy absorbed by the gas generally depends on the polarization of the incident radiation. It is noted that when the polarizations of the saturating and probe radiations are different, deviations from the usual saturation effect may be observed.

Hui Chen, Hebin Li, Yuri V. Rostovtsev +3 more

We study sub-Doppler saturation resonances at cesium molecular transitions in the absorption band B1Πu ← X1∑g+ near 780 nm by using a commercial diode laser. The saturation power is measured as low as 5.7 mW with the laser beam diameter of 0.1 cm. Optical saturation is associated with the optical pumping of molecular ground-state levels. The long relaxation time of ground-state levels could attract interest to electromagnetically induced transparency and quantum state memory in the molecular gas. We propose to use the molecular transitions as references for doubled-frequency sources in the communication band around 1550 nm.

Vladilen S Letokhov, V. P. Chebotaev

Elena S. Ostapenko, Ледовских Дмитрий Васильевич, Н. Н. Рубцова

Saturated absorption resonances in a gas 13CH3F at the vibration-rotation transition R(4,3) 0–1 of vibration mode ν3 detected in a probe radiation wave transmission in a presence of unidirectional saturating wave are investigated. The width of saturated absorption resonances is increasing with the growth of saturating radiation intensity. In the limit of strong saturation, the resonance shape differs from Lorentzian one by the sharper decrease in the wings, and the resonance width allows to estimate the dipole transition moment d = 0.045 D in good agreement with literature data for this transition of 13CH3F

М. P. Kulish