Characterization of regenerative stabilized actively mode-locked fiber laser incorporating a saturated amplifier in feed-back chain

• Regenerative stabilization scheme incorporating saturated amplifier in feedback chain.
• Pulse width, energy jitter and the super-mode noise respect to detuning parameters.
• Comparison between systems with and without regeneration in the presence of forced vibrations.

An actively mode-locked fiber laser with regenerative stabilization established through a feed-back electronic amplifier operated in the saturation regime is reported in this paper. Compared to the regenerative stabilization schemes that employ phase-locked loops (PLL), a saturated amplifier has been used for inhibiting the transmission of amplitude noise through the feed-back chain. Such a laser system has been constructed, studied and characterized as a function of its design variables. Specifically, the electronic phase shift in the feed-back circuit and the RF power applied to the modulator have been varied to study their effect on the mode-locked pulse train. The influence of these parameters on super-mode noise is studied and the optimum values of phase shift and RF power of the recovered carrier at which the noise is found to be a minimum (−48 dB) has been determined. A comparison of systems with and without regenerative mode-locking under controlled conditions reveals that a regenerative system has at-least an order of magnitude better noise performance compared to a system without regeneration.