Semiconductor saturable absorber mirrors (SESAMs) have become a key element of many
ultrafast laser sources, enabling passively modelocked lasers with> 100 GHz repetition rate
or with> 10 μJ pulse energy. Precise knowledge of the nonlinear optical reflectivity is
required to optimize the SESAMs for self-starting passive modelocking at record high
repetition rates or pulse energies. In this article, we discuss a new method for wide dynamic
range nonlinear reflectivity measurements. We achieve a higher accuracy (< 0.05%) with a …

… This is achieved by integrating a semiconductor saturable absorber into a mirror structure.
The important … We present a new tool for characterizing the nonlinear reflectivity of
SESAMs with a higher accuracy and lower constraints on electronic equipment. Instead of
two photodiodes and two high-end lock-in amplifiers only one photodiode, a simple
amplifier and an AD converter is needed. Despite the simple and cost-efficient approach, an …