Compact low-noise passively mode-locked Er-doped femtosecond all-fiber laser with 2.68 GHz fundamental repetition rate.

Abstract

A passively mode-locked Er-doped fiber laser with a fundamental repetition rate of 2.68GHz is reported. The oscillator operating at a central wavelength of 1558.35nm has a compact, robust structure and low-noise performance. The timing jitter integrated from 30MHz down to 300Hz is 82.5fs, and the timing jitter performance is analyzed based on the theory model. The amplification and compression of the high repetition rate optical pulses are also investigated. After a three-stage amplifier, the average power is boosted to 430mW. Meanwhile, based on the nonlinear self-phase modulation effect, the spectral bandwidth is broadened from 7.56 to 19.2nm, and the corresponding pulse width is compressed to 244fs.