Color center lasers passively mode locked by quantum wells

Using multiple-quantum-well (MQW) saturable absorbers, a NaCl color center was passively mode locked to produce 275-fs transform-limited, pedestal-free pulses with a peak power as high as 3.7 kW. The pulses are tunable from lambda =1.59 to 1.7 mu m by choosing MQWs with different bandgaps. The output pulses from the laser were shortened to 25 fs using the technique of soliton compression in a fiber. The steady-state operation of the laser requires the combination of a fast saturable absorber and gain saturation.>