40 GHz actively modelocked polarisation maintaining erbium fibre ring laser

The first polarisation-maintaining actively modelocked erbium fibre ring laser (ML-EFRL) operating at a base rate of 40 GHz is presented. The laser generates highly stable and virtually transform-limited 1.2–1.9 ps pulses tunable over 40 nm with a timing jitter of < 0.1 ps. These represent the shortest pulses and lowest timing jitter generated by a 40 GHz ML-EFRL.