Stable High Power Narrow Linewidth Single Frequency Fiber Laser Using a FBG F-P Etalon and a Fiber Saturable Absorber

We experimentally demonstrated a stable high power narrow linewidth single frequency fiber ring laser. In laser cavity, a fiber Bragg grating Fabry-Perot (FBG F-P) etalon acts as reflector and mode-selecting device to reduce the longitudinal-mode density greatly, while short polarization-maintaining (PM) Er3+ -doped fiber (EDF) serves as a saturable absorber to suppress mode hopping and stabilize frequency effectively. Using Er3+/Yb3+ co-doped fiber and pumping by two multi-mode laser diodes at 975nm, stable single frequency laser at 1549.8nm was acquired. The presented fiber laser exhibited output power of 923.6mW was obtained upon 3.4W pump power. The corresponding optical-optical efficiency was 27.2% and the SNR was great than 50dB. The 3dB linewidth of the presented laser was about 5.0 kHz, measured by the delayed self-heterodyne method with 30-km single mode fiber.