Generation 1.7-ps mode-locked pulse with low RF linewidth from A 1.55 µm vecsel operating at 25 °C

A 1.55 μm VECSEL with a hybrid metal-GaAs/AlAs metamorphic mirror optimized for high power room temperature operation has been assembled with a fast InGaAsN/GaAsN saturable absorber mirror (SESAM) to generate mode-locked pulses at a frequency of 2 GHz. Nearly Fourier transform-limited pulses are obtained at 25 °C avoiding the need for water cooling, with a pulsewidth ; 2 ps. The RF linewidth of the free running laser has been measured to be less than 1000 Hz, showing the potentiality of external cavity semiconductor disk lasers to generate mode-locked pulse train at 1.55 μm with an intrinsic low timing-jitter.