We propose and experimentally demonstrate an accurate modulation-format-indepen-dent and cascaded filtering effect (CFE) insensitive in-band optical signal-to-noise ratio (OSNR) monitoring technique enabled by Gaussian process regression (GPR) utilizing a widely tunable optical bandpass filter (OBPF) and optical power measurements. By adjusting the center frequency of a widely tunable OBPF and measuring the corresponding output optical power as the input features of GPR, the proposed OSNR monitoring technique is experimentally proven to be transparent to modulation formats and robust to CFE, chromatic dispersion (CD), polarization mode dispersion (PMD), and nonlinear effect (NLE). Experimental results for 9-channel 32Gbaud PDM-16QAM signals with 50GHz channel spacing demonstrate OSNR monitoring with the root mean squared error (RMSE) of 0.429 dB and the mean absolute error (MAE) of 0.294 dB, in the OSNR range of -1∼30 dB. Even better, our proposed technique has the potential to be employed for link monitoring at the intermediation nodes and can eliminate the necessity to know the transmission information.

中文翻译：

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使用高斯过程回归的具有级联滤波效果的拉曼放大多跨系统，使用与调制格式无关的带内OSNR监视技术

我们提出并通过实验证明了一种精确的调制格式独立和级联滤波效应（CFE）的不敏感带内光信噪比（OSNR）监测技术，该技术通过利用广泛可调的光学器件的高斯过程回归（GPR）实现带通滤波器（OBPF）和光功率测量。通过调节可广泛调谐的OBPF的中心频率并测量相应的输出光功率作为GPR的输入特征，该OSNR监视技术在实验上被证明对调制格式是透明的，并且对CFE，色散（CD），偏振具有鲁棒性模式色散（PMD）和非线性效应（NLE）。具有50GHz通道间隔的9通道32Gbaud PDM-16QAM信号的实验结果表明，OSNR监测的均方根误差（RMSE）为0。在-1〜30 dB的OSNR范围内为429 dB，平均绝对误差（MAE）为0.294 dB。更好的是，我们提出的技术有可能被用于中介节点的链路监视，并且可以消除了解传输信息的必要性。