Bimolecular mean frequency absorption

SYNERGISTIC EFFECTS IN TWO-PHOTON ABSORPTION THE QUANTUM ELECTRODYNAMICS OF BIMOLECULAR MEAN-FREQUENCY ABSORPTION... 

Following theoretical developments (Andrews and Harlow 1983, 1984a), bimolecular mean-frequency absorption was next discovered by researchers working on the photodynamics of charge transfer reactions. For example, Ku et al. (1983) performed studies on gaseous mixtures of xenon and chlorine passed through a laser fluorescence cell. The proposed reaction mechanism... 

Bimolecular mean-frequency absorption is a nonlinear process which results entirely from the effects of molecular proximity, although wavefunction... 

As mentioned above, there are four specific cases of bimolecular mean frequency absorption that are of special interest. These are distinguished by the type of mechanism (cooperative or distributive) involved and whether the photons absorbed have the same or different frequencies. The latter condition is in most cases determined by whether a single laser beam or two laser beams are employed for the excitation. We consider first the single-beam cases. 

Synergistic Effects In Two-Photon Absorption The Quantum Electrodynamics Of Bimolecular Mean-Frequency Absorption 39... 

From an experimental point of view, the doable-beam process allows a greater flexibility, in that some choice can be exercized in the individual frequencies of the two laser beams, subject to the satisfaction of Eq. (4.5). It is therefore normally possible to avoid tuning either laser to a frequency that might swamp the bimolecular process with conventional single-photon absorption. The utilization of resonances with in ermediate energy levels (see Section X) is also facilitated by the ability to tune one of the lasers while keeping the mean value of the two laser frequencies fixed. 

---