Complete characterization of quantum-limited timing jitter in passively mode-locked fiber lasers

We characterize the timing jitter of passively mode-locked, femtosecond, erbium fiber lasers with unprecedented resolution, enabling the observation of quantum-origin timing jitter up to the Nyquist frequency. For a pair of nearly identical 79.4MHz dispersion-managed lasers with an output pulse energy of 450pJ, the high-frequency jitter was found to be 2.6fs [10kHz, 39.7MHz]. The results agree well with theoretical noise models over more than three decades, extending to the Nyquist frequency. It is also found that unexpected noise may occur if care is not taken in optimizing the mode-locked state.