Radiation redistribution, collisional

Collisional redistribution of radiation. A system A + B of two atoms /molecules may be excited by absorption of an off-resonant photon, in the far wing of the (collisionally) broadened resonance line of species A. One may then study the radiation that has been redistributed into the resonance line - a process that may be considered the inverse of pressure-broadened emission. Interesting polarization studies provide additional insights into the intermolecular interactions [118, 388]. 

K. Burnett and J. Cooper. Collisional redistribution of radiation II. The effects of degeneracy on the equations of motion for the density matrix. Phys. Rev. A, 22 2027-2043... 

A small molecule has been previously defined as a system of discrete molecular levels interacting with a radiation field in the absence of other dissipative continua (predissociation, preionization, collisional relaxation). The excited system may thus decay uniquely by the radiative path, and the emission quantum yield Q must be equal to one if measured in a sufficiently broad spectral range. On the other hand, the s-l coupling, inducing redistribution of the s) level oscillator strength, always implies a lengthening of the fluorescence lifetime of mixed levels with respect to that of a pure s> state. 

Collisional Redistribution of Radiation Collision Induced Fluorescence... 

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