Influence of the resonant self-action and nonstationary coherent effects on the characteristics of a frequency-modulated laser beam

摘要

Self-action of a frequency-modulated laser beam, propagating through a two-level saturable absorber, is modeled numerically basing of the direct solution of Maxwell-Bloch equations. Following the common idea of spectroscopy, we plot the output intensity versus the input laser frequency that periodically changes in time. At modulation frequencies comparable with the relaxation rates the hysteresis loop is observed, i.e. the dependence of the transmitted intensity upon the instantaneous frequency depends on the direction of the frequency change. At large amplitudes of modulation coherent transient oscillations of the output intensity are observed.