Experimental realization of nonlinear polarization evolution mode-locking in polarization maintaining fibers

Abstract

Nonlinear Polarization Evolution (NPE) — a passive mode-locking technique — is successfully used in many all-fiber ultrafast oscillators. It is based on a temporal filtration of the pulse polarization state affected by a self-action due to the instantaneous Kerr nonlinearity. To work properly, most of NPE based architectures of fiber lasers contain pieces of standard optical fibers or bulk optical elements, which makes them susceptible to temperature changes and mechanical perturbations. We present a novel NPE mode-locker implementation based on Polarization Maintaining (PM) fibers resolving this problem. The all-PM-fiber all-normal-dispersion femtosecond oscillator has been developed using such an artificial saturable absorber (SA).