Long cavity ring fiber mode-locked laser with decreased net value of nonlinear polarization rotation.

We investigate a new configuration of a mode-locked fiber laser by using a nonlinear polarization rotation-based design to generate soliton pulses with low repetition rate. Unlike with previously reported configurations, we introduce a Faraday mirror after the first half of the cavity length to counteract the nonlinear polarization rotation effects. The total cavity length is 437 m including a 400-m long twisted SMF-28 fiber.

Initial conditions for dissipative solitons in a strict polarization-controlled passively mode-locked Er-Fiber laser.

We report the dynamics of dissipative solitons in a ring cavity passively mode-locked fiber laser with a strict control of the polarization state. We study the relation between the polarization state of the pulses propagating in the cavity and the regimes of generation. We have found that at pulse ellipticities between 5° and 15°, the laser generates one bunch of pulses in the cavity, while at higher ellipticities the laser generates multiple bunches.

Instantaneous frequency measurement of dissipative soliton resonant light pulses.

We measured the instantaneous frequency profile of two different dissipative soliton resonant (DSR) light pulses, the usual flat-top and less-common trapezoid-shaped light pulses. The DSR light pulses were provided by an ytterbium-doped polarization-maintaining fiber ring passively mode-locked laser using the adequately selected amount of net-normal dispersion. We confirmed that the DSR light pulses have a (moderately) low linear chirp across the pulse, except at the edges, where the chirp changes exponentially.

Polarization evolution of vector wave amplitudes in twisted fibers pumped by single and paired pulses.

Nonlinear polarization dynamics of single and paired pulses in twisted fibers is experimentally and numerically studied. Accompanying a dramatic difference in the output spectrum when a single- or double-amplified soliton pulse is launched in the fiber, the output polarization for the two cases also reveals very different characteristics.

Dissipative soliton resonance in a full polarization-maintaining fiber ring laser at different values of dispersion.

We investigated the dissipative solitons resonance in an ytterbium-doped fiber ring laser in which all the elements are polarization maintaining (PM). A semiconductor saturable absorber mirror was used as a mode-locker. The cavity included a normal dispersion single-mode fiber (SMF) and an anomalous dispersion photonic crystal fiber.