Tunable 40 GHz mode-locked semiconductor fiber laser using a nonlinear optical loop mirror

We demonstrate a tunable 40 GHz mode-locked semiconductor fiber laser incorporating a nonlinear optical loop mirror. The laser is tunable over the C-band and generates picosecond pulses with a timing jitter less than 710 fs.

1. Introduction

Wavelength tunable sources capable of producing short pulses are of interest for optical signal processing and high-speed optical communications systems. Such pulses have been generated using nonlinear optical loop mirrors (NOLMs) as all-optical modulators to mode-lock fiber lasers [1],[2]. The potential for performing ultrafast all-optical signal processing operations such as all optical clock recovery (AOCR) with NOLMs has also been investigated [3], [4]. In this paper, we demonstrate a tunable semiconductor fiber laser (SFL) that is optically mode-locked using a NOLM at 40 GHz. In particular, we investigate the wavelength tenability and timing jitter, as well as the impact of filter bandwidth on the output pulses. These results can be used to optimize the laser for AOCR at 40 Gb/s.