Diagrammatic Technique for Calculating Radiation of Coherently or Incoherently Excited Two-Level Atoms

摘要

A diagrammatic technique is developed for calculating the radiation from two-level atoms excited by coherent or incoherent pulses. The method is practical for excitation fields of arbitrary magnitude. Multiple pulse configurations involving both temporally separated or overlapping pulses with either parallel or non-parallel propagation directions are readily accommodated. Those pulses which are incoherent can be either correlated or uncorrelated. The technique is suitable for the analysis of time-delayed four-wave mixing with intense incoherent excitation fields. The method is demonstrated by treating several practical examples.