A self-frequency-locked multi-wavelength erbium-doped fibre ring laser

Abstract

A self-frequency-locked laser in a 1.55 mu m band is demonstrated by adding a segment of samarium-doped fibre (SDF) into an erbium-doped fibre (EDF) ring laser cavity. The narrow band output signal, with a 3 dB down line width of less than 0.15 nm and a side-mode suppression ratio larger than 30 dB, is nearly polarization independent. A multi-wavelength EDF ring lasersource, using a 1 x n synchronous optical switch and n segments of SDF with different lengths, is proposed.