Controlling Narrow Bandwidth Soliton in Fiber Laser via Ta ₂ PdSe ₆ Optical Polarizer

ABSTRACT Narrow bandwidth soliton (NBS) fiber lasers hold great potential in applications such as quantum optics, molecule excitation, and cavity soliton actuation. However, achieving stable and controllable NBS fiber lasers is challenging due to dispersion and the nonlinear effects inherent in fiber lasers. We have successfully developed a simple and controlled NBS fiber laser by incorporating a Ta 2 PdSe 6 optical polarizer with polarization‐dependent characteristics. Bandwidth narrowing is achieved through the filtering effect due to polarization absorption, and NBS switching benefits from polarization transmission selection. The controlled modulation of two separate NBS states corresponds to 3 dB bandwidths of 0.39 and 0.44 nm, with corresponding pulse widths of 10.2 and 9.1 ps, respectively. The time‐bandwidth product is approximately 0.49, which is close to the Fourier transform limit. Numerical simulations provided detailed insights into the dynamical evolution of NBS modulation. Our findings illustrate the potential of optical polarizers based on anisotropic materials for laser modulation, paving the way for the development of stable and controllable NBS fiber lasers with straightforward designs.