-L-Band Ring Erbium Doped Fiber Amplifier with Fiber Bragg Grating

Abstract

An optical gain-clamped long wavelength band (1570  1610 nm) erbium-doped fibre amplifier (L-band EDFA) is demonstrated using a fiber Bragg grating. It uses a counter propagating ring resonator, in order to achieve constant gain with minimum gain variation. The clamped-gain Level can be controlled to be in the range from 7.2 to 14.3dB by increasing the cavity loss from 0 to 20dB. It is found that at 10dB variable optical attenuator (VOA) loss, clamping of the gain is flat with variation of input signal power from â€â€40 to â€â€5dBm. The gain measured is 10.9dB, which is 30% less than the open ring gain of 15.3dB at a pumping power of 92mW. The noise figure measured is about 52dB. The proposed design prevents oscillating light from being coupled out, but it degrades the amplifier’s noise figure and clamped gain as the dynamic range is increased.