Polarization-controlled interconversion among birefringence-managed, dissipative, and conventional solitons in a hybrid-cavity erbium-doped fiber laser.

We demonstrate a polarization-controlled hybrid-cavity erbium-doped fiber laser that reproducibly supports birefringence-managed solitons (BMSs), dissipative solitons (DSs), and conventional solitons (CSs). The two coupled branches share an erbium-doped fiber and a single-walled carbon nanotube saturable absorber, but differ in dispersion and birefringence. In the net-normal-dispersion branch containing a short segment of polarization-maintaining fiber (PMF), tuning the launched polarization switches the output between near-chirp-free BMSs with resonant sidebands and strongly chirped DSs with broad, steep-edged spectra. In the PMF-free net-anomalous-dispersion branch, CSs with Kelly sidebands are obtained. Coupled Ginzburg-Landau simulations reproduce the observations and indicate that coupling at the interface between single-mode fiber and PMF, together with PMF-induced walk-off, governs the vector-component evolution and determines whether resonant sidebands are generated or suppressed in the net-normal-dispersion branch.