2025/11/12 by Kang 康 Li 李, Shuo Li, Qingping Hu +15
Physics and Astronomy · Engineering · #Advanced Fiber Laser Technologies #Photonic Crystal and Fiber Optics #Photorefractive and Nonlinear Optics
paper · doi:10.1088/0256-307x/42/12/120407
Abstract Currently, the performance, cost, and environmental sustainability of saturable absorbers (SAs) represent major bottlenecks in the development of ultrafast fiber lasers. However, the development of high-performance SAs remains challenging due to intricate fabrication processes and inadequate nonlinear performance. In this context, this work presents the natural alkaloid berberine as a promising alternative for mode-locked erbium-doped fiber lasers. The berberine-based SA exhibits excellent nonlinear optical properties, including a modulation depth of 24.40% and a saturation intensity of 1.281 MW/cm 2 , and successfully enables stable femtosecond pulse generation. By employing time-stretched dispersive Fourier transform technology, the transient dynamics results indicate that the berberine-based SA significantly shortens the relaxation oscillation time and effectively suppresses pulse intensity fluctuations, thereby accelerating the self-starting process of mode-locking. This work provides a new strategy for developing high-performance, low-cost, and environmentally friendly ultrafast photonic devices, significantly advancing the practical application of green SAs.