High-quality optical pulse train generation at 80 Gb/s using a modified regenerative-type mode-locked fiber laser

Abstract

In this paper, we present an experimental demonstration of a high-quality optical pulse train generation at 80 Gb/s. The successful operation was achieved via two steps. In the first step, an ultrastable 2-ps (FWHM), 40-Gb/s pulse train was generated using the technique of fourth-order rational harmonic mode locking. The mode-locked laser was stabilized using a regenerative-type base-line extraction feedback technique. In the second step, an external fiber loop mirror consisting of several meters of polarization-maintaining fiber was used to double the repetition rate from 40 to 80 Gb/s. The output of the 80-Gb/s pulse train shows very small pulse-to-pulse amplitude fluctuation with good long-term stability.