Resonant Saturable Absorber Mirrors for Dispersion Control in Ultrafast Lasers

We discuss a concept for incorporating dispersion compensation into a saturable absorber mirror. This integrated device relies on an absorber layer embedded in a resonator structure and can provide negative dispersion of several 1000 fs², similar to the spectral phase characteristics of a Gires-Tournois interferometer. A similar integration is possible also for semiconductor gain structures, as they are employed in semiconductor disk lasers. We will provide a detailed analysis of the dispersion compensation capacities of our approach, linking dispersion scaling and nonlinear properties of the device. The theoretical part will be illustrated by dispersion measurements on prototypical devices. We believe that our concept paves the way for fully integrated vertical semiconductor femtosecond lasers but may also find numerous applications in solid state lasers and femtosecond fiber lasers