We evaluate the commutation relations and quantum-mechanical Langevin equations satisfied by two-level operators in the case of exponential decay of the driving field. We rewrite the dynamical equation in the form of a difference equation by Laplace transformation. From the solution of the difference equation, the instantaneous resonance fluorescence spectrum is calculated.
© 1993 Optical Society of America
Weisi Tan, Weihan Tan, Dongsheng Zhao, and Renghong Liu, "Instantaneous resonance fluorescence spectrum of a two-level system for an exponential decay of the driving field," J. Opt. Soc. Am. B 10, 1610-1619 (1993)