title: Simple all-PM-fiber laser mode-locked with a nonlinear loop mirror.
abstract: In this Letter, we present a figure-eight all-PM-fiber laser oscillator design with a nonlinear optical loop mirror as an artificial saturable absorber. Unlike previous constructions using the same mode-locking technique, our cavity is constructed entirely of polarization-maintaining (PM) fibers, making the oscillator more resistant to thermal and mechanical perturbations. Two simple and robust laser configurations that differ by the output coupling ratio (70% or 30%) are presented. The first configuration delivers high energy pulses of 3.5 nJ, and the second configuration delivers pulses of 1.6 nJ at a common repetition rate of 15 MHz. In either configuration, the pulsed operation is stable, and the laser operates in a single pulse train regime, even for pump powers approaching twice the power required for mode-locking. We have also observed that, at higher intracavity powers, stimulated Raman scattering plays a significant role.
authors.forename: Jan
authors.initials: J
authors.lastname: Szczepanek
authors.forename: Tomasz M
authors.initials: TM
authors.lastname: Kardaś
authors.forename: Maria
authors.initials: M
authors.lastname: Michalska
authors.forename: Czesław
authors.initials: C
authors.lastname: Radzewicz
authors.forename: Yuriy
authors.initials: Y
authors.lastname: Stepanenko