Stable Active-Passive Mode Locking of a Nd: Glass Laser Using #5 Saturable Dye

Abstract

While the stability of passively mode locked Nd:YAG lasers has been greatly improved through use of intracavity acoustooptic loss modulators, relatively little attention has been given to the Nd:glass laser, especially in the very short pulse regime [1-6]. In this hybrid approach, the active loss modulation reduces the inherent statistical nature of the early stage pulse build up, while retaining the effect of the saturable absorber as nonlinear loss element and Q switch for final stage pulse shortening. In this paper, we report on active—passive mode locking of a Nd:phosphate glass laser through use of the new #5 saturable absorbing dye, which has enabled generation of ~6 ps duration transform-limited pulses largely free of occurrences of satellite pulse structure.