Double-pass Erbium-doped Fiber Research Articles

Cost-effective double pass erbium doped fiber amplifier with an embedded dispersion compensation module and all-optical gain control for wavelength-division multiplexing applications

We present a cost-effective double-pass erbium-doped fiber amplifier (EDFA) configuration with an embedded chromatic dispersion compensation fiber and optical gain control function. The amplifier was characterized and tested over a 100-km 10 Gb/s×C-band 16-channel wavelength division multiplexing system and demonstrated excellent performance.

Comparison of the characteristics of double-pass erbium-doped superfluorescent fiber sources obtained from different flattening techniques

We investigate and compare the characteristics of erbium-doped superfluorescent fiber sources (SFS's) obtained from the use of different flattening techniques in double-pass forward (DPF) and double-pass backward (DPB) configurations. The intrinsic flattening technique consists of optimizing the length of the erbium-doped fiber. The extrinsic flattening methods include the addition of a samarium-doped fiber (SDF) and a fiber-Bragg-grating (FBG) notched filter at the output end separately to shape the SFS spectrum. Although intrinsically flattened DPF and DPB SFS's have a large output power of >34 mW, they are accompanied by an approximately 3-dB ripple. The FBG-flattened DPF and DPB SFS's can achieve a wide linewidth of 35 nm with a small ripple of approximately 1.7 dB and better pump-power-dependent mean-wavelength stability; SDF-flattened DPF and DPB SFS's are inferior because of the SDF's lossy spectrum.