L-Band Harmonic Mode Locking of Single-, Two-, and Three-Soliton Bunches from C-Band Amplifier in a Figure-of-Eight Fiber Laser

摘要

We report the experimental emission above 1.6 μm of harmonic mode locking of single-, two-, and three-soliton bunches in a C-band Er:Yb codoped silica fiber laser. The laser cavity consists of two connected fiber loops in the figure-of-eight configuration. In such a system the mode-locking regime arises spontaneously due to the nonlinear optical loop mirror, which acts as a saturable absorber. The 1.6 μm oscillation is enhanced by minimizing the linear intra-cavity losses. Depending on the pump power and the polarization controllers, the laser generates harmonic mode locking above 1.6 μm containing patterns with one, two or three pulses. These two last regimes have not been achieved so far at a long-wavelength range.