Wavelength-tunable erbium fiber ring laser in single-frequency operation utilizing Fabry–Perot laser with Sagnac cavity

Abstract

We propose and demonstrate experimentally a stabilized and wavelength-selective erbium-doped fiber ring laser in single-longitudinal-mode operation with Fabry–Perot laser diode (FP-LD) and using a tunable bandpass filter (TBF) inside and outside a Sagnac ring cavity. The side-mode suppression ratios of 21dB and 36.5dB and the output power of –3.6dBm and –8.7dBm in the wavelengths of 1524.45–1562.35nm and 1531.07–1562.35nm with the tuning step of 1.4nm can be achieved when the TBF outside and inside Sagnac loop, respectively. The output wavelength variation of zero and the output power fluctuation of <0.1dB are also obtained. Moreover, the transmission efficiency of the ring laser has also been performed experimentally under a 1.25, 2.5 and 10Gb/s external modulation, respectively.