Measurement of the timing jitter and pulse energy fluctuation of a PLL regeneratively mode-locked fiber laser

We measured the timing jitter and pulse energy fluctuation from the noise RF power spectra of a 10-GHz regeneratively mode-locked erbium-doped fiber laser in both free-running and phase-locked-loop (PLL) operation. The measured timing jitter was 90 and 120 fs for free-running and PLL operation, respectively. These values are to our knowledge the smallest timing jitter reported in actively mode-locked fiber lasers. The pulse energy fluctuation was 0.24% for both operation.