Stretched-pulse generation in all-fiber mode-locked erbium-doped fiber laser using Lawsone dye saturable absorber

Abstract

This paper describes the generation of mode locked pulses by an erbium-doped fiber laser (EDFL) cavity with a Lawsone dye saturable absorber (SA). The Lawsone SA is made of a piece of thin film, which is obtained using a liquid-phase exfoliation method. Characterization of the film reveals that its saturation intensity and modulation depth are 2.9 MW/cm2 and 12 % respectively. When the Lawsone SA is added to the EDFL cavity, a stable mode-locked pulse train is achieved at 1567.5 nm wavelength. The laser operates within a pump power of 33.6 mW to 43.3 mW at a repetition rate of 3.4 MHz and pulse width of 1.47 ps. The results indicate that the Lawsone dye can be used as a SA for laser pulse generation.