Tunable and stable single-frequency fiber laser by applying Rayleigh feedback light and saturable absorber filter

Abstract

In this study, a stable and tunable erbium-doped fiber (EDF) ring laser architecture is demonstrated. To filter the dense longitudinal-mode noises and achieve the single-longitudinal-mode (SLM) performance, the Rayleigh backscattering (RB) feedback injection and unpumped EDF saturable absorber (SA) induced filter is applied inside the ring cavity. Here, an effective wavelength-selection scale of the EDF laser is achieved between 1528.0 and 1576.0 nm, when C-band EDF based gain-medium is utilized. Additionally, the wavelength linewidth, optical signal to noise ratio (OSNR), output power and output stability of the fiber laser are also discussed over the available wavelength range in the measurement.