Simultaneously gain-flattened and gain-clamped erbium fiber amplifier

Abstract

In this paper, we propose and demonstrate a simple erbium amplifier module based on an erbium- doped fiber amplifier (EDFA) and an erbium-doped waveguide amplifier (EDWA) in serial, having gain-flatted (GF) and gain-clamped (GC) functions simultaneously. In first proposed GF amplifier scheme, the maximum gain variation of 2.5 dB can be observed in the effective range of 1528 to 1562 nm and the entire gains are above 35 dB with the input signal power of -30 dBm. Hence, we investigate second scheme by optical feedback method in the proposed fiber amplifier achieving gain-flattened (GF) and gain-clamped (GC) efficiencies simul- taneously. Thus, the maximum gain variations of ± 0.8 and ± 1.8 dB can be obtained in the operating range of 1530 to 1564 nm, when the input signal powers are -16 and -40 dBm, respectively. Moreover, the dynamic gain profile can be adjusted and dynamic input power range is also measured based on the proposed GF and GC fiber amplifier.