Scaling high-power ultrafast VECSELs into the femtosecond regime

The combination of high output power and femtosecond pulses from VECSELs and MIXSELs would be very attractive for many applications. To explore the limitations, a quantitative understanding of the pulse formation processes is required. Our numerical simulations showed a good qualitative agreement with experimental results in the picosecond regime. By minimizing intracavity group delay dispersion (GDD) and improving gain bandwidth and SESAM parameters, our model predicts pulses as short as 250 fs. As a first step we minimized GDD with a top coating which provides values between +/- 10 fs(2) over a range of 30 nm around the design wavelength.