  Rapid progress in passively mode-locked fiber lasers is currently driven by
the recent discovery of vector feature of mode-locking pulses, namely, the
group velocity-locked vector solitons, the phase locked vector solitons, and
the high-order vector solitons. Those vector solitons are fundamentally
different from the previously known scalar solitons. Here, we report a fiber
laser where the mode-locked pulse evolves as a vector soliton in the strong
birefringent segment and is transformed into a regular scalar soliton after the
polarizer within the laser cavity. The existence of solutions in a
polarization-dependent cavity comprising a periodic combination of two distinct
nonlinear waves is novel and likely to be applicable to various other nonlinear
systems. For very large local birefringence, our laser approaches the working
regime of vector soliton lasers, while it approaches scalar soliton fiber
lasers under the conditions of very small birefringence.
