Passive mode locking and Q switching of an erbium 3 μm laser using thin InAs epilayers grown by molecular beam epitaxy

Passive mode locking and Q switching has been achieved for the first time in an Er3+:YSGG laser at λ=2.8 μm using ultrathin single-crystal InAs epilayers grown on GaAs substrate which were subsequently bombarded with 15 keV protons at a dose of 1013 cm−2. The bleaching effect was due to a dynamic Moss–Burstein mechanism with a fast (<100 ps) recovery time. In the case of passive mode locking, pulses of 10 MW power were generated at λ=2.8 μm.