A flat L band Er doped fiber amplifer clamping gain by backward C band amplified

A flat high gain L-band gain-clamped erbium-doped fiber amplifier (GC-EDFA) by using backward C-band amplified spontaneous emission (ASE) is proposed. It uses two stages of EDFs pumped forward as gain media, and a broadband chirp fiber Bragg grating (CFBG) to reflect the backward C-band ASE back int