Passive mode-locked cesium diode-pumped alkali laser

A first, to the best of our knowledge, demonstration of passive mode-locking in diode-pumped alkali laser (DPAL) is reported in this paper. An intracavity cesium vapor cell, buffered by atmospheric pressure methane, is used to passively mode lock a continuously pumped cesium DPAL with a static gain medium. A train of short pulses with duration less than 460 ps was observed using a 2.0-GHz bandwidth detector that limited the real time duration measurements. The calculated minimum duration for these pulses is 57 ps.