Abstract

Optical systems such as lasers, parametric oscillators, and fluorescing atoms are examples of open quantum systems; each of these systems involves dissipation in an essential way. In theoretical quantum optics two main approaches are used to treat such systems. The first, the master equation approach, uses the Schrodinger picture, where a density operator describes the state of the system. The second, the quantum-Langevin approach, uses the Heisenberg picture; in this approach damping terms appear explicitly in the Heisenberg equations of motion, together with noise operators that prevent the decay of the commutation relations.

© 1992 IQEC