Multiple Quantum Well Passive Modelocking of NaCl Color Center Laser

Abstract

We passively modelocked a NaCI color center laser (CCL) by using multiple quantum well (MQW) saturable absorbers to produce pulses around 260fsec. The laser is an all solid-state source lasing around 1.6-1.7μm and formed in a single cavity. Silberberg, et al. [1], first modelocked a semiconductor diode laser using MQW’s, and Haus and Silberberg [2] theorized that the fast saturable absorber component plays a major role in the formation of their ~ 1.5psec pulses. This fast absorber component results from MQW absorption bleaching by short-lived excitons formed near the band gap of the MQW. The excitonic lifetime of 200±30fsec measured in our MQW’s [3] is comparable to our pulse widths. Consequently, the fast saturable component dominates the pulse shaping and may limit the pulse width in our experiments.