Journal of the Physical Society of Japan
Second Order Optical Process of a Three-Level System in Contact with a Nearly Gaussian-Markoffian Noise Bath
Yoshitaka Tanimura, Tetsuhiro Suzuki, Ryogo Kubo
Abstract
A general formulation is given for the second order optical process of a three-level system in contact with a heat bath consisting of harmonic oscillators with a proper frequency spectrum producing a Markoffian random perturbation. Elimination of the bath using the influence functional method of Feynman and Vernon yields a continuous fraction expression and the result affords a basis to clarify the relation between the stochastic and dynamical approaches to treat the partial destruction of the quantum coherence of the optical process. As an example, a three-level system with intermediate-state interaction is treated in some detail.