Radiation Theory for Two-Photon Processes

N. Bloembergen

Lezhi Lo, C. K. Law

We present a nonrelativistic theory of quantum radiation generated by shaking a two-level atom in vacuum. Such radiation has the same origin of photon emission in dynamical Casimir effect. By performing a time-dependent ``dressing'' transformation to the Hamiltonian, we derive an interaction term that governs the radiation. In particular, we show that photon pairs can be generated, not only by shaking the position of the atom, but also by changing the internal states of the atom. As applications of our theory, we calculate the emission rate from an oscillating atom and the multiphoton state generated in a single-photon scattering process.

G. L. Gurevich, Yu. G. Khronopulo

M. M. Sushchinskiǐ

The general theory of stimulated radiation is applied to four-photon coherent Raman scattering. A comparison with the theory of the two-photon scattering is presented. Some peculiarities of the stimulated Raman scattering such as radiation asymmetry, replication effects, rings of the Raman components are considered based on the theory for coherent processes. Copyright © 2000 John Wiley & Sons, Ltd.

Deng-Yu Zhang

The interaction of a two-level atom with a thermal radiation field for single-photon processes and two-photon processes without rotating wave approximation is analysed. The atom's reduced density matrix is calculated when the quantum theory in small system coupled to thermal reservoir is used. The decoherence properties of atom is analyzed.[WT5HZ]