L-band all-optical gain-clamped erbium-doped fiber amplifier via ASE reflection technique

We present an L-band all-optical gain-clamped erbium-doped fiber amplifier with a fiber-loop mirror as the ASE reflector. By using the combination of a C/L-band wavelength division multiplexer (WDM) and fiber-loop mirror, the backward C-band amplified spontaneous emission (ASE) is reflected back into the erbium-doped fiber and works as the control light. The static gain level of this amplifier can be adjusted by changing the ASE feedback. The experimental results show that the EDFA gain can be effectively clamped via this ASE reflection technique.