Submarine optical transmission systems are commonly operated with constant output power amplifiers. The Gaussian Noise (GN) model of propagation was generally developed in the context of constant gain amplification and accounts for amplified spontaneous emission (ASE) noise and nonlinear interference (NLI) noise. Recently, new models have been proposed and developed to predict signal-to-noise ratio (SNR) models for systems with constant output power amplification that account for the phenomenon known as signal droop, or more broadly, generalized droop (GD). Here we describe a GD model within the context of noises as generated in the GN model, and then further including other distributed noise generation such as might occur for crosstalk in multicore optical fibers. The model results in simple expressions for SNR, signal power, and noise powers as a function of the number of identical spans. We provide numerical modeling confirmation of the analytical model for different formats, and experimental transmission data that is fully consistent with the model.

中文翻译：

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恒定输出功率放大器系统广义下垂的 SNR 模型和实验测量


海底光传输系统通常使用恒定输出功率放大器来运行。高斯噪声 (GN) 传播模型通常是在恒定增益放大的背景下开发的，并考虑了放大自发发射 (ASE) 噪声和非线性干扰 (NLI) 噪声。最近，人们提出并开发了新模型来预测具有恒定输出功率放大的系统的信噪比 (SNR) 模型，该模型解释了信号下降或更广泛的广义下降 (GD) 现象。在这里，我们在 GN 模型中生成的噪声的背景下描述 GD 模型，然后进一步包括其他分布式噪声生成，例如多芯光纤中的串扰可能发生的情况。该模型得出 SNR、信号功率和噪声功率的简单表达式，作为相同跨度数量的函数。我们提供不同格式的分析模型的数值建模确认，以及与模型完全一致的实验传输数据。