Research on Bismuth-Doped Fiber Lasers in the 1150-1200nm Band

With the gradual development of laser technology, early gas lasers and solid-state lasers were marked by substantial size, low efficiency, inadequate heat dissipation, and the necessity for intricate optical path adjustments. These constraints-imposed limitations on their applications in domains such as industry and medicine. The wavelength range of traditional rare-earth ions is limited. Due to the multi-valence states of bismuth ions and their multiple splitting characteristics in different matrix fields, bismuth-doped optical fibers exhibit an extremely wide coverage band. Therefore, bismuth (Bi) ions have become a current research hotspot. Given that ytterbium ions have a low luminous efficiency in the 1150 - 1200 nm wavelength band, this paper conducts a numerical simulation study on the dynamic characteristics of bismuth-doped fiber lasers in the 1150 - 1200 nm wavelength band. This experiment is based on the three-level rate equation model and the boundary value problem solution method to establish a theoretical model of aluminosilicate bismuth-doped fiber lasers. By analyzing the mutual relationships among the pump power, fiber length, and output power, the threshold characteristics and gain saturation phenomenon of bismuth-doped lasers in this band are verified.