抄録
A highly efficient and low noise gain-clamped long-wavelength-band erbium-doped fiber amplifier (L-band EDFA) is demonstrated using a ring laser in double-pass system. The broadband fiber Bragg grating (FBG) operating at L-band region is used to retro-pass the test signal into the system for enhanced gain. A length of forward pumped EDF is incorporated in front of the double-pass amplifier to achieve a low noise figure. The gain clamping is achieved by routing the backward ASE into the feedback loop to create ring laser. The gain is clamped at 18.6dB from -40 to -8dBm with gain variation of less than ±0.1dB and a noise figure of less than 6dB.
