Generation of switchable and tunable rectangular pulse and multi-pulse with different peak power at L band

• lei huang, Boxin Li, Dongfang Jia, and Chunfeng Ge
• received 02/04/2024; accepted 04/22/2024; posted 04/24/2024; Doc. ID 520957
• Abstract: A novel L-band erbium-doped fiber laser, utilizing a nonlinear optical loop mirror (NOLM) as mode-locker, is presentedin this study. Through precise adjustments of the polarization controllers (PCs), the laser achieves the generation ofrectangular pulses with distinct single wavelengths, λ1=1593 nm and λ2=1571 nm, as well as dual-wavelength operation.The laser's operational mode can extend further to include harmonic mode-locking (HML). Furthermore, theinvestigation reveals the emergence of trapezoidal pulses and low-peak-power rectangular pulses within proximity of theconventional rectangular pulses. Notably, the evolutions of these low peak power pulses with the pump power also adhereto the peak power clamping (PPC) effect. Remarkably, the relative positioning of these pulses remains consistent acrossvarying pump power levels or harmonic orders. Intriguingly, the evolution of the trapezoidal pulse with respect to pumppower stands in stark contrast to that of the h-shaped pulse.