Abstract

A negative feedback stabilisation technique was utilised to extend the operating parameter range of a diode end-pumped Nd:KGd(WO₄)₂ laser mode-locked by saturable Bragg reflectors. In continuous-wave pump mode, stabilisation was used to suppress Q-switching instabilities. The influence of the modulation depth of the saturable absorber on output pulse duration was evaluated. In this way, bandwidth-limited pulses of 5.3 ps duration were obtained. In quasi-continuous wave regime, negative feedback stabilisation was used to damp the turn-on relaxation oscillations as well as Q-switch instabilities. The on-time output power was substantially scaled up yielding 12-ps pulses with 5 W on-time average output power at 44% optical slope efficiency.

© 2004 Optical Society of America