Analysis of saturable absorbers,interacting with gaussian pulses

Mode-locked lasers, Q-switch systems and discrimination amplifiers make use of saturable absorbers. The interaction of those absorbers with light pulses is well known, either for very long or very short pulses, but not, if the pulse width is comparable with the absorber life time, which occurs very often in experiments. Moreover, the spatial structure of the pulse is mostly not considered. In this paper, we investigate in detail the interaction of gaussian pulses (spatial and temporal) with the two-level-absorber. Energy transmission, pulse shortening and pulse asymmetry are calculated as functions of pulse width and small signal transmission of the absorber.