Hybridized Active Fiber and Fiber Amplifier for Broadband Coherent Optical Communication

Abstract The rapid developments of technologies create an urgent requirement for increasing the capacity of the optical fiber communication system. The most promising way is to extend the communication wavebands. Here, it is reported that the hybridized Er‐doped active fiber (EDF) and Er‐doped fiber amplifier (EDFA) devices present broadband optical response. The EDF consists of a cross‐linked ‐Si─O‐ and ‐P─O‐ network, which leads to great inhomogeneous broadening and wide net gain from 1575 to 1625 nm. The EDFA devices are constructed by gain‐clamped strategy and broadband amplification is realized. The booster is successfully fabricated with a gain above 25 dB and a flatness below ±0.86 dB from 1575 to 1620 nm at the input signal power between −13 and 0 dBm. The pre‐amplifier has also been constructed with a gain above 20 dB and a flatness around ±0.3 dB at the input signal power from −40 to −25 dBm. Furthermore, the practical application of the hybridized EDFA device for high‐capacity coherent transmission is demonstrated. The results reveal a novel idea to realize gain‐flattened amplification and provide a valuable solution for the new generation of high‐capacity coherent communication systems.