A passively Q-switched laser constructed by a two-mirror reentrant ring cavity

A passively Q-switched laser is demonstrated by a two-mirror reentrant and unidirectional ring cavity. Due to the cavity configuration, the pulse-to-p ulse timing jitter is effectively reduced to less than 3% over 40,000 shots . As indicated in our simulation on photon dynamics in the cavity, spontane ous noise from the gain medium is the major cause of large timing jitter in passively Q-switched lasers, and it is eliminated in this laser.