Gain switching of a Nd(+3)-doped fiber laser

We report the generation of gain-switched pulses near 1.06 microm from a Nd(+3)-doped single-mode fiber pumped at 590 nm. For a 5-cm-long fiber, pulses of 100 nsec at a 1-MHz repetition rate were obtained. For a 1-cm-long fiber, the pulse shortened to 40 nsec at repetition rates of up to 2.5 MHz for a single, independently drivable relaxation oscillation.