Dual-wavelength mode-locked erbium fiber laser utilizing a Ge-PCF saturable absorber

In this work, we demonstrate a mode-locked erbium-doped fiber laser (EDFL) based on germanium-core doped photonic crystal fiber (Ge-PCF) as a passive saturable absorber (SA). The proposed SA was incorporated inside the PCF core during the manufacturing process. The short length of the proposed high nonlinear fiber can achieve a stable mode-locked pulse by controlling the fiber and collapsing lengths. The proposed Ge-PCF has been integrated into an erbium-doped fiber ring laser to establish the desired ultrashort pulse with the merits of a short interaction length (<3 cm), enhanced damage threshold, environmental robustness, ease of manufacture, and suitable mass production. The obtained output pulses at FWHM have a pulse width of 800 ps and a repetition rate of similar to 19 MHz. Furthermore, the EDFL based on Ge-PCF achieved a dual-wavelength output spectrum with narrow bandwidths centered at 1557.27 and 1558.81 nm. The short-pulse capabilities of the proposed fiber laser make it highly suitable for a wide range of photonic applications. (c) 2024 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.