1.9 μm mode-locked fiber laser based on evanescent field interaction with metallic vanadium diselenide (VSe2)

Abstract

A stable passively mode-locked Thulium/Holmium-doped fiber laser (THDFL) was demonstrated by depositing layers of vanadium diselenide (VSe2) onto a D-shaped fiber using the drop-casting method. The VSe2-coated D-shaped fiber was then incorporated into the ring cavity as a saturable absorber (SA). The cavity has a net dispersion of -1.37 ps2 while the central wavelength of the output spectrum was 1912 nm with a full width at half-maximum (FWHM) of 2.9 nm. The pulse repetition rate was 11.6 MHz with the pulse width of ∼1.4 ps at the maximum pump power. The fundamental frequency of the mode-locked output had a signal-to-noise ratio (SNR) of ∼47 dB. These results indicate that the metallic TMD VSe2 can serve as an effective SA in optical fiber laser applications at the 2.0 μm region.