Additive-pulse mode locking of a diode-pumped Nd:YLF laser

Abstract

We investigate the passive self-starting technique of additive-pulse mode locking of a diode-laser-pumped Nd:YLF laser. Pulses of 1.5-psec duration at a repetition rate of 123 MHz have been obtained, using only a single-mode optical fiber in an external feedback cavity to achieve pulse formation. The sech² pulses are approximately transform limited and to our knowledge the shortest that have been produced by a Nd:YLF laser. The laser was pumped by two 1-W laser-diode arrays and had usable output power of 20 mW, corresponding to a peak power of 108 W.