324-fs Pulses From a SESAM Modelocked Backside-Cooled 2-<i>μ</i>m VECSEL

We present the first modelocked backside-cooled GaSb VECSEL (Vertical External Cavity Surface Emitting Laser) operating above $2 ~\mu \text{m}$ . Using a two quantum well InGaSb SESAM (SEmiconductor Saturable Absorber Mirror) in V-shaped cavity arrangement we obtain femtosecond modelocking at center wavelength of 2061 nm, with pulses as short 324 fs, an average output power high 65 mW repetition rate 3 GHz. An operation picosecond regime is further demonstrated even higher up to 260 and 4.5-ps pulses. perform characterization both femto- regimes measurements pulse duration, optical spectrum, (frequency time domain analysis) low power. In this context, influence intracavity group delay dispersion (GDD) investigated. find that GDD has strong on duration (fs or ps regime) thus performance our SESAM-modelocked 2- notation="LaTeX">$\mu VECSEL.