Sub-60-fs, 1300-nm Laser Pulses Generation from Soliton Self-Frequency Shift Pumped by a Femtosecond Yb-Doped Fiber Laser

We report on the generation of 1300-nm ultrashort laser pulses via the soliton self-frequency shift in a high-nonlinearity fiber, pumped by the 41.9-MHz, 67.9-fs, 1073-nm femtosecond laser emitted from an Yb-doped fiber laser system. A numerical simulation was applied to investigate the spectral broadening process driven by the soliton self-frequency shift with increased pump power. The experimental results are in good agreement with the numerical results, delivering a 33-mW, 57.8-fs 1300-nm Raman soliton filtered by a longpass filter. The impact of the polarization direction of the injected pump laser on the soliton self-frequency shift process was also further investigated. The root means squares of the the Yb-doped fiber laser and the nonlinearly spectral broadened laser were 0.19%@1h and 0.23%@1h, respectively.