A novel gain-clamped long wavelength band (L-band) erbium-doped fiber amplifier (EDFA) is proposed and experimented by using a fiber Bragg grating (FBG) at the input end of the amplifier. This design provides a good gain clamping and decreases noise effectively. It uses two sections of erbium-doped fiber (EDF) pumped by a 1480-nm laser diode (LD) for higher efficiency and lower noise figure (NF). The gain is clamped at 23 dB with a variation of 0.5 dB from input signal power of -30 to -8 dBm for 1589 nm and NF below 5 dB is obtained. At the longer wavelength in L-band higher gain is also obtained and the gain is clamped at 16 dB for 1614 nm effectively. Because the FBG injects a portion of backward amplified spontaneous emission (ASE) back into the system, the gain enhances 5 dB with inputting small signal.
© 2006 Chinese Optics Letters
(050.2230) Diffraction and gratings : Fabry-Perot
(060.2410) Fiber optics and optical communications : Fibers, erbium
(060.2430) Fiber optics and optical communications : Fibers, single-mode
(140.3560) Lasers and laser optics : Lasers, ring
Tianshu Wang, Yubin Guo, Hongwei Yan, Yuhang Wang, and Ke Wang, "Low noise gain-clamped L-band erbium-doped fiber amplifier by utilizing fiber Bragg grating," Chin. Opt. Lett. 4, 636-638 (2006)