0.5-GHz Repetition Rate Fundamentally Tm-Doped Mode-Locked Fiber Laser

Abstract

We demonstrate a passively mode-locked Tm-doped silica fiber laser with 535-MHz fundamental repetition rate by employing a semiconductor saturable absorber mirror. With in-band pumping at 1590 nm, the stable mode-locked fiber laser produces up to 50 mW at an incident pump power of 558 mW. The laser operating at 1938 nm has a spectral bandwidth of 0.72 nm. After amplification, the laser pulse width is measured to be ∼7.9 ps, and the time-bandwidth product is ∼0.46.Index Terms-High repetition rate, mode-locking, Tm-doped silica fiber laser.

Advances and Challenges of Ultrafast Fiber Lasers in 2–4 µm Mid‐Infrared Spectral Regions

“…With the development of MBE thin-film growth technology, quantum well/barrier structured GaSb-SESAMs have gradually become ideal mode-locking elements for mid-IR fiber lasers. [144][145][146][147][148][149][150][151][152][153] In 2007, Kivisto et al first realized a wavelength-tunable 750 fs soliton pulse in the range of 1912-1972 nm, and a 150 fs narrow soliton pulse at 2150 nm in a Tm 3+ /Ho 3+ codoped fiber laser based on InGaSb-SESAM, with an average power up to 230 mW. [12] Since then, 2 μm band mode-locked fiber lasers based on SESAM have been extensively reported.…”

14.5 GHz passive harmonic mode-locking in a dispersion compensated Tm-doped fiber laser

“…A direct method to achieve high repetition rate mode-locking is of improving the fundamental repetition rate by shortening the cavity length. Tm-doped mode-locked linear fiber lasers with fundamental repetition rate of 253 MHz 8 , 535 MHz 9 and 982 MHz 10 have been demonstrated by this way with a cavity length of ~40 cm, ~18.7 cm, and ~10 cm, respectively. Very recently, an 5.9 cm linear Tm-doped fiber cavity mode-locked by a semiconductor saturable absorber mirrors was proposed to increase the fundamental repetition rate to 1.6 GHz, which is the highest repetition rate around 2 µm as we best known 11 .…”