Nonlinear Response of Saturable Absorber Mirrors for Different Operation Regimes

In this study, we show how the nonlinear response of a saturable absorber depends on the parameters of the optical pump pulses. The result suggests that it should always be specified at what conditions the semiconductor saturable absorber mirror (SESAM) reflectivity has been measured. Another important consequence resulted from this analysis is that the saturation fluence of SESAM could be very different for different operation regimes, for example, for mode-locking and Q-switching. We propose a simple method of testing the absorption recovery time by using optical pulses with different pulsewidths