SGER: Distributed Erbium-Doped Fiber Amplifiers

掺铒光纤放大器的最新进展 （掺铒光纤放大器）已用于光波 通信系统可以被称为 “集总”（EDFA）放大器。 这是 因为几十dB的增益 纤维长度为50 m。 是 很明显，信号经历了很大的 振幅偏移，这可能导致 信道间干扰严重， WDM系统 所需要的是一种 整体分布放大 光纤的长度，因此， 单位长度正好抵消了 光纤衰减 这将允许 信号保持在高电平 整个系统，同时减少 放大自发辐射（ASE） 从而导致更高的信噪比 系统的信噪比（SNR）。 先前的一样 一份初步的报告， 提出了分布式掺铒光纤放大器（DEDFA） 最近由AT T贝尔实验室的一个团队完成）。 他们证明了纤维确实可以 通过控制极低的铒掺杂 十亿分之10-100（ppb） 平均在核心，需要这样的 分布式放大 进一步没有 显著的杂质或其它缺陷被 引入纤维， 环境损失，由于 辐射，不会妨碍它们的使用。 由于思想的重要性， DEDFAs，在此方面的理论研究， 建议将针对两个部分：（一） 优化DEDfa的设计，以及（ii） 分析其在光波中的性能 通信系统，无论是直接- 检测和相干检测，以便 确定最终的系统， 构建，涉及权衡。

To date the Erbium Doped Fiber Amplifiers (EDFAs) which have been used in lightwave communications systems can be termed as "lumped" (EDFA) amplifiers. This is because several tens of dBs of gain is obtained in fiber lengths 50 m. It is evident that the signal experiences large excursions in amplitude, which can cause significant interchannel interference in a WDM system. What is needed is a distributed amplification over the whole length of the fiber, so that the gain per unit length just cancels the intrinsic fiber attenuation. This will allow the signal to be maintained at a high level throughout the system, while reducing the Amplified Spontaneous Emission (ASE) and thus resulting in a higher Signal-to-Noise Ratio (SNR) for the system. The first, and a somewhat preliminary, report of such Distributed EDFAs (or DEDFA) was presented recently by a team at AT&T Bell Labs). They showed that fibers can indeed be made with the controlled, very low erbium doping levels, 10-100 parts per billion (ppb) averaged over the core, required for such distributed amplification. Further no significant impurities or other defects are introduced into the fiber, and the environmental added losses, due to radiation, will not impede their use. Due to the importance of the idea of DEDFAs, the theoretical study in this proposal will aim at two part: (i) optimizing the design of the DEDfa and (ii) analyzing its performance in lightwave communication systems, both direct- detection and coherent-detection, so as to determine the ultimate system that can be built, with trade-offs involved.