Generation of Dual-Wavelength Optical Domain–Wall Dark–Bright Pulses by Composite Filtering Effects

Optical domain–wall (DW) solitons have attracted considerable attention for their special applications in wavelength-division multiplexing and signal processing in optical communications. In this study, we construct a dispersion-managed fiber laser with a composite filtering effect composed of nonlinear polarization rotation (NPR) filtering and Lyot filtering for achieving dual-wavelength domain–wall dark–bright pulses. Our optical-domain dark–bright pulse is characterized by even, though it has two optical wavelength components, still has the same repetition frequency. The phenomenon of dual-wavelength dark and bright pulses occurs by adjusting the composite filtering, and the dark and bright pulses can be separated by continuing the filtering. Our work presents a novel approach to achieve dual-wavelength domain–wall dark–bright pulses.