Soliton pulse generation in thulium-doped fiber laser incorporating nickel-H3BTC-MOF mode locker

This paper demonstrates the generation of optical pulses utilizing a mode locker (ML) based on Nickel-1,3,5-benzene-tricarboxylic acid-metal-organic framework (Ni-H 3 BTC-MOF) in a thulium-doped fiber laser (TDFL). An evanescent field interaction between the material and the propagating light was ensured by using a tapered fiber as a waveguide structure for the ML construction. A composite of Ni-H 3 BTC-MOF and polydimethylsiloxane was prepared and transferred to the tapered fiber using a spin-coating technique. The prepared ML was characterized for nonlinear saturable absorption properties, exhibiting a modulation depth of 2.00% and a saturation fluence of 2.65 μJ/cm 2 . A mode-locked soliton pulse at 1931.94 nm lasing wavelength with a spectral bandwidth of 3.30 nm was emitted at 1109 mW pump power. The fabricated ML demonstrated a stable mode-locked pulse with a signal-to-noise ratio (SNR) of 46 dB and maintained operational stability for 1 hour with a standard deviation of 0.03 ps in the time domain.