Optical communication systems, operating in C–band, are reaching their theoretically achievable capacity limits. An attractive and economically viable solution to satisfy the future data rate demands is to employ the transmission across the full low–loss spectrum encompassing O, E, S, C, and L band of the single mode fibers (SMF). Utilizing all five bands offers a bandwidth of up to $\sim$53.5 THz (365 nm) with loss below 0.4 dB/km. A key component in realizing multi–band optical communication systems is the optical amplifier. Apart from having an ultra–wide gain profile, the ability of providing arbitrary gain profiles, in a controlled way, will become an essential feature. The latter will allow for signal power spectrum shaping which has a broad range of applications such as the maximization of the achievable information rate × distance product, the elimination of static and lossy gain flattening filters (GFF) enabling a power efficient system design, and the gain equalization of optical frequency combs. In this paper, we experimentally demonstrate a multi–band (S+C+L) programmable gain optical amplifier using only Raman effects and machine learning. The amplifier achieves $>$1000 programmable gain profiles within the range 3.5 to 30 dB, in an ultra–fast way and a very low maximum error of $1.6 \cdot 10^{-2}$ dB/THz over an ultra–wide bandwidth of 17.6–THz (140.7–nm).

中文翻译：

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多波段可编程增益拉曼放大器

在 C 波段运行的光通信系统正在达到其理论上可实现的容量极限。满足未来数据速率需求的一种有吸引力且经济可行的解决方案是在包括单模光纤 (SMF) 的 O、E、S、C 和 L 波段在内的整个低损耗频谱上进行传输。利用所有五个频段可提供高达$\sim$53.5 THz (365 nm)，损耗低于 0.4 dB/km。实现多频段光通信系统的关键部件是光放大器。除了具有超宽的增益曲线外，以受控方式提供任意增益曲线的能力将成为一个基本特征。后者将允许具有广泛应用的信号功率谱整形，例如最大化可实现的信息速率 × 距离乘积，消除静态和有损增益平坦滤波器 (GFF)，实现节能系统设计，以及光频梳的增益均衡。在本文中，我们通过实验演示了仅使用拉曼效应和机器学习的多波段 (S+C+L) 可编程增益光放大器。放大器达到$>$3.5 至 30 dB 范围内的 1000 个可编程增益配置文件，以超快的方式和非常低的最大误差 $1.6 \cdot 10^{-2}$ 17.6-THz (140.7-nm) 超宽带宽上的 dB/THz。