Narrowing of two-photon resonance due to elastic collisions
Ulybin V. A., Chebotaev V. P.
The two-photon absorption line shape is examined in the field of a standing wave with elastic collisions. A sharp decrease is observed in the transit broadening of the two-photon resonance in vibrational-rotational transition of molecules due to an increase in the interaction time of particles with the electromagnetic field as a result of elastic collisions. This effect permits obtaining supernarrow optical two-photon absorption resonances with high intensity in a low-pressure gas.