PbS-doped phosphate glasses saturable absorbers for 1.3-μm neodymium lasers

Passive mode locking and saturable absorber Q-switching of neodymium lasers at 1,3 mum with PbS-doped phosphate glasses are demonstrated. Q-switched pulses of 120 ns (0.1 muJ) in duration (energy) and the average output power of 3 mW from a quasi-cw diode-pumped Nd3+:KGW laser and ultrashort pulses of a maximum of 250 muJ in energy and 150 ps in duration from a Nd3+:YAP laser were obtained. The bleaching decay rate of the samples was found to increase with the Quantum Dot's size decreasing due to the enhancement of quantum confinement effects for smaller dots and stronger overlapping of the electron and trap state wave functions.