Stable High SNR Narrow Linewidth Linear Cavity Single-Wavelength Er-Doped Fiber Laser

Abstract

A stable high signal to noise ratio (SNR) narrow linewidth linear cavity single-wavelength Er-doped fiber laser is reported. In the experiment, we used a fiber Bragg grating Fabry-Perot (FBG F-P) etalon and a Fiber Loop Mirror (FLM) as the reflectors of the laser cavity, and used a length of 4m Er-doped fiber as the saturable absorber to suppress mode hopping and stabilize frequency effectively. An all fiber polarization controller (PC) was used to restrain spatial hole burning effect in gain fiber. Using a length of 3m Er-doped fiber pumped by a laser diode at 975nm, stable single-wavelength laser at 1544.714nm was acquired, and the 3dB linewidth of laser was 0.013nm. The corresponding threshold of laser was 30mW, the SNR was as high as 70dB, and the slope efficiency was about 0.5%.