Low Threshold Self-Starting Operation of an Additive-Pulse Mode-Locked, Diode-Pumped Nd:YLF Laser

Abstract
The birefringence effect of a single mode fiber on the self-starting threshold in a diode-pumped, additive-pulse mode-locked Nd:YLF laser is investigated. By controlling the polarization state of pulses in the external cavity containing a single-mode fiber, the mode locking could be self-started with CW power (as low as 10 mW) coupled to the fiber and stably maintained over several hours.