We present in this study a PM all-fiber laser oscillator passively mode-locked (ML) at 1.03 μm. The laser is based on
Nonlinear Polarization Evolution (NPE) in polarization maintaining (PM) fibers. In order to obtain the mode-locking
regime, a nonlinear reflective mirror including a fibered polarizer, a long fiber span and a fibered Faraday mirror (FM) is
inserted in a Fabry-Perot laser cavity.
In this work we explain the principles of operation of this original laser design that permits to generate ultrashort pulses
at low repetition (lower that 1MHz) rate with a cavity length of 100 m of fiber. In this experiment, the measured pulse
duration is about 6 ps. To our knowledge this is the first all-PM mode-locked laser based on the NPE with a cavity of
100m length fiber and a delivered pulse duration of few picosecondes.
Furthermore, the different mode-locked regimes of the laser, i.e. multi-pulse, noise-like mode-locked and single pulse,
are presented together with the ways of controlling the apparition of these regimes. When the single pulse mode-locking
regime is achieved, the laser delivers linearly polarized pulses in a very stable way.
Finally, this study includes numerical results which are obtained with the resolution of the NonLinear Schrodinger
Equations (NLSE) with the Split-Step Fourier (SSF) algorithm. This modeling has led to the understanding of the
different modes of operation of the laser. In particular, the influence of the peak power on the reflection of the nonlinear
mirror and its operation are studied.