1 015-1 046 nm tunable femtosecond Yb-doped fiber laser

In recent years, ultra-fast ytterbium doped mode-locked fiber lasers have been widely used in industrial processing, medical surgery, multiphoton imaging and other fields due to their high conversion efficiency, convenient operation, free maintenance and compact size. Compensation of group velocity dispersion in lasers was an effective method to obtain picosecond or femtosecond pulses. A grating pair and a spectral filter were used to adjust the dispersion and spectral width of laser wavelength in cavity flexibly, the laser can output stable mode-locked pulses with the corresponding fundamental repetition frequency of 19.41 MHz. The central wavelength can be adjusted from 1015 nm to 1037 nm when the net cavity dispersion was +0.0127 ps². In the case of +0.007 ps² dispersion, the central wavelength can be adjusted from 1015 nm to 1045 nm and when the net cavity dispersion was −0.0127 ps², the central wavelength can be adjusted from 1020 nm to 1046 nm. Meanwhile, when the net cavity dispersion changed from abnormal to nearly zero dispersion, the spectral bandwidth can be adjusted from 1.40 nm to 19.38 nm, and the corresponding pulse width after compression can be adjusted from 1.03 ps to 175.9 fs. The proposed and demonstrated scheme is capable of continuously adjusting the state of the laser, and is expected to be used in the development of a femtosecond laser front-end with high power and high energy, which can meet the application requirements of lasers with a alterable of spectrum widths and wavelengths.