Tunable pulse dynamics in a spun fiber filter-assisted ultrafast laser

Wavelength-tunable and dual-wavelength mode-locked lasers have broad applications across scientific research and industrial optics. Here, we present what we believe to be a novel spun fiber filter-assisted ultrafast laser with tunable pulse dynamics, employing a hybrid mode-locking and pulse-picking method. The proposed fiber laser delivers femtosecond ultrashort pulses with a tunable wavelength range of 21.9 nm within the optical communication band, controlled via polarization adjustment. Moreover, the laser supports three various forms of dual-wavelength dichroic pulse dynamics, including dual-wavelength single-soliton dichroic states, as well as dichroic structures formed by tightly bound soliton molecules in combination with single solitons. Beyond its potential as a versatile ultrashort pulsed light source for applications such as dual-comb spectroscopy and high-precision sensing, the demonstrated laser system also serves as a dissipative platform for exploring complex nonlinear dynamics in polychromatic regimes.