Ultrawide-bandwidth optical amplification over almost 90 nm, covering the C+L bands, is described. Complemented by system-tailored geometrical constellation shaping and nonlinearity compensation, it enabled a record capacity transmission of 74.38 Tb/s over 6,300 km of G.654 single-mode fibre. The hybrid scheme, combining backward Raman pre-amplification with EDFA, significantly improves the average effective noise figure across the entire bandwidth, allowing the use of span lengths of 70 km. The system-tailored GS-64QAM constellation was optimised to both linear link impairments and transceiver nonlinearities, improving the gap to the AWGN channel capacity relative to square 64QAM from 0.6 bit/symbol to 0.35 bit/symbol. We experimentally evaluated the system performance using the bit-wise achievable information rate (AIR) and signal-to-noise ratio (SNR) at the end of transmission, as well as post SD-FEC BER.

中文翻译：

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通过 C+L 放大和几何形状的 PDM-64QAM 在 6300 公里单模光纤上实现 74.38 Tb/s 传输

描述了几乎 90 nm 的超宽带光学放大，覆盖了 C+L 波段。辅以系统定制的几何星座整形和非线性补偿，它在 6,300 公里的 G.654 单模光纤上实现了 74.38 Tb/s 的创纪录容量传输。混合方案将反向拉曼预放大与 EDFA 相结合，显着提高了整个带宽的平均有效噪声系数，允许使用 70 公里的跨度长度。系统定制的 GS-64QAM 星座针对线性链路损伤和收发器非线性进行了优化，将与 AWGN 信道容量相对于方形 64QAM 的差距从 0.6 位/符号提高到 0.35 位/符号。