Low-Noise, Robust, All-Polarization-Maintaining Mode-Locked Er-Doped Fiber Ring Laser

We report on a low-noise, robust, all-polarization-maintaining (PM) mode-locked Er-doped fiber ring laser, indicating an effective method to further optimize the phase noise by adjusting the pump power. Integrated from 10 Hz to 10 MHz, the optimized timing jitter is as low as 269 fs with an amplitude noise of 0.028%. The experimental results agree well with the prediction in a series of simulations and numerical analyses, revealing that the phase noise performance is improved by rebalancing the interactions between the gain, dispersion, and nonlinearity, and the high pulse energy and short pulse duration contribute to a reduction in the phase noise until the nonlinearities begin to neutralize the benefit. Consisting of a packaged semiconductor saturable absorber mirror and an all-PM-fiber ring structure, the laser performs well with reliable output pulses in vibrational environments, and most of the technical noise from external disturbances is also suppressed.