Yb-doped Mode-locked Laser Research Articles

Tunable-wavelength broadband spectrum dissipative soliton mode-locked fiber laser

The tunable-wavelength broadband spectrum dissipative soliton (DS) is demonstrated in Yb-doped mode-locked laser using an all-fiber structure saturable absorber (SA), that is, graded index multimode fiber (GIMF)-step index multimode fiber (SIMF)-GIMF with 4.70% modulation depth and 4.55 mW saturation power. Increasing pump power alters intra-cavity balance between loss and gain and nonlinear and dispersion, causing wavelength adjustment and spectrum broadening. The center wavelength shifts towards shorter wavelength with rang of 1037.77–1024.83 nm, corresponding 3-dB bandwidth widens from 6.10 to 9.23 nm and pulse width narrows from 23.80 to 13.38 ps. The signal-to-noise ratio (SNR) is 71.2 dB at the repetition rate of 14.63 MHz. The GIMF-SIMF-GIMF structure has a huge potential to serve as both SA and filter component for the tunable-wavelength broadband spectrum Yb-doped mode-locked fiber laser (MLFL), which is favorable for developing the field of nonlinear microscopy and material processing.

Dual wavelength generation and wavelength tunability in Yb-doped mode-locked laser using few-mode fiber as a saturable absorber

In this research, we demonstrate wavelength tunability and dual wavelength generation in all-fiber ytterbium (Yb)-doped mode-locked laser using a single mode–few-mode–single mode fiber (SMF–FMF–SMF) combination act as a saturable absorber (SA). The all-fiber SA exhibits high modulation depth of 34.53% and a saturation intensity of 9.17 MW/cm2. The SMF–FMF–SMF structure encompasses an inherent filtering along with SA property. By combining the tunable intra-cavity birefringence of the laser with the SA features result in dual-wavelength generation and wavelength tunability. Thus, the tuning of center wavelength of output spectrum from 1028.88 through 1076.18 nm, with the compressed pulse widths from 319 to 324 fs respectively, is achieved. Besides, the generated dual-wavelength is switched from 1033.32/1058.2 nm to 1049.7/1075.7 nm, respectively. These results indicate that an all-fiber SMF–FMF–SMF structure is a potential SA element for wavelength tunability and dual-wavelength mode-locking in Yb-doped fiber lasers, which can be used for nonlinear microscopy, bio-degradable material processing and terahertz spectroscopy.

Yb系モード同期レーザーによる高繰り返し光周波数コム

Yb系モード同期レーザーによる高繰り返し光周波数コム