GaAs based semiconductor quantum dot saturable absorber mirror grown by molecular beam epitaxy

A Quantum-dot saturable absorber mirror (QD-SAM) has been fabricated by the molecular beam epiiaxy (MBE) technique. Preliminary measurements show that our QD-SAM is a very promising candidate for passive mode-locking a fiber laser or a solid state laser with wavelength in the range of 970-1090nm. The 22%-33% dips in the reflectivity spectrum are observed, which are attributed to quantum dot absorption, indicating the potential for a large modulation depth and hence generation of ultra-short laser pulses through mode-locking.