空芯光纤系统中的逐信道发射功率优化：利用解耦的功率预算

中文摘要 AI 辅助

在单模光纤（SMF）中，逐信道发射功率并非自由的设计变量。Kerr效应通过自相位调制（SPM）限制每个信道的功率，而交叉相位调制（XPM）、四波混频（FWM）和信道间受激拉曼散射（ISRS）将所有信道的发射功率与其传输质量耦合，需要对发射功率分布进行联合优化。空芯光纤（HCF）的Kerr系数比石英光纤低三到四个数量级，使得逐信道功率几乎成为独立的设计变量，主要受共享的放大器输出预算约束。我们为放大的HCF链路开发了一个逐信道广义信噪比（GSNR）模型，该模型包括放大自发辐射（ASE），其中掺铒光纤放大器的噪声系数依赖于波长和输出功率，还包括模间干扰、EDFA尾纤中的非线性失真、二氧化碳气体线路损耗以及依赖于波长的收发机上限。我们还推导了一个灵敏度定律，用于预测发射功率整形何时有益：可实现的增益受ASE噪声占比的限制，在SMF工作点附近被Kerr非线性抵消，而在HCF中保持为正。对于跨越400-3200公里的80信道、64-GBaud C波段链路，逐信道优化相对于平坦发射将最差信道GSNR提高了最多1.1 dB，与SMF相比将跨信道功率灵敏度降低了一到两个数量级，并且以约11 dB更低的放大器输出功率实现给定的GSNR。在固定的放大器输出预算下，这一优势使得在GSNR目标为20-23.4 dB时，最差信道传输距离延长1.6-2.9倍，而相同的优化对受非线性限制的SMF链路的传输距离延长最多仅为9%。

英文摘要

In single-mode fiber (SMF) the Kerr effect ties every channel's quality of transmission to its neighbors' launch powers through cross-phase modulation (XPM), four-wave mixing (FWM) and inter-channel stimulated Raman scattering (ISRS), forcing a jointly planned launch profile. Hollow-core fiber (HCF), with a Kerr coefficient three to four orders of magnitude below silica, turns the per-channel powers into nearly independent knobs limited only by the shared amplifier budget. We build a per-channel generalized signal-to-noise ratio (GSNR) budget for amplified HCF links, including amplified spontaneous emission (ASE) with a wavelength- and output-power-dependent erbium-doped fiber amplifier (EDFA) noise figure (NF), inter-modal interference (IMI), nonlinearity in amplifier pigtails, CO2 gas-line loss and a flat transceiver (TRx) noise ceiling, and derive a sensitivity law that predicts when power shaping pays: its gain is bounded by the ASE noise share, canceled by self-phase modulation (SPM) at the SMF single-channel optimum, and positive in HCF. Across 80x64-GBaud C-band links over 400-3200 km, per-channel optimization buys up to 1.0 dB of worst-channel GSNR over a flat launch as the EDFA NF spread grows to 4 dB, cuts cross-channel power sensitivity by more than two orders of magnitude relative to SMF, and reaches a given GSNR at about 3 dB lower aggregate amplifier output. At a fixed amplifier budget this becomes a 1.26 to 1.41 times worst-channel reach extension, against at most 15% on the nonlinearity-capped SMF link.

发表机构

• Huawei Technologies Canada（华为加拿大技术有限公司）

机构由 AI 辅助整理，请以论文原文为准。