Triple-wavelength mode-locked laser based on a Cr2Si2Te6 saturable absorber.

• We used Cr 2 Si 2 Te 6 combined with a tapered fiber as SA to couple into an erbium-doped fiber laser. • A triple-wavelength fiber laser is generated with a novel Sagnac loop structure. In this work, a Cr 2 Si 2 Te 6 -based tapered fiber saturable absorber with a modulation depth of 4.7 % and a saturable intensity of 28.67 MW/cm2 was fabricated by liquid-phase exfoliation. A triple-wavelength erbium-doped mode-locked fiber laser with a Sagnac loop structure was successfully generated. Its output wavelengths were 1560.2, 1561.3, and 1562.8 nm. The basic repetition rate was 0.97 MHz, corresponding to a signal-to-noise ratio of 49 dB. This is the first demonstration of a triple-wavelength mode-locked fiber laser focusing on a two-dimensional ferromagnetic insulator Cr 2 Si 2 Te 6. This experiment shows that this triple-wavelength mode-locked fiber laser has excellent performance. [ABSTRACT FROM AUTHOR]