Non-intrusive measurement of In-Band OSNR of high bitrate polarization-multiplexed signals

et al. 2022

In the optical communication systems, the optical spectrum (OS) provides useful informations for optical performance monitoring and optical link diagnosis. In this paper, we investigate the neural-network based OS analysis (OSA) techniques able to simultaneously recognize the OS and estimate the optical signal to noise ratio (OSNR), cascaded filtering distortion (CFD) and carrier wavelength drift (CWD). We demonstrate that, compared with the multi-task artificial neural network (MT-ANN) and convolutional neural network (MT-CNN), the proposed multi-task cascaded ANNs (CANN) and cascaded CNNs (CCNN) can greatly improve the OSA performance and accelerate the training process by exploiting specific features and loss functions for different tasks. The CCNN able to deal with the high-resolution OS (HOS) can further improve the OSA performance compared with the CANN. The averaged OS recognition accuracy and OSNR, CFD and CWD estimation errors obtained with the CCNN (CANN) for the 15 kinds of optical signals are 99.32% (97.07%), 0.36 (0.55) dB, 0.24 (0.32) and 0.04 (0.06) GHz, respectively, even when the various OS distortions are present. The proposed CANN and CCNN with a better versatility, higher OSA accuracy and faster convergence speed are promising enabling techniques for the future intelligent OSA systems.

Section: Introductionmentioning

confidence: 99%

Multi-Functional Optical Spectrum Analysis Using Multi-Task Cascaded Neural Networks

Wang

et al. 2022

“…Recently reference optical spectrum (ROS) based in-band OSNR monitoring methods have attracted much attention as they are more cost-effective and robust [15]- [20]. These methods rely on the widely deployed OSA [15] or just a simple tunable optical band-pass filter (OBPF) in combination with an optical power meter [18]. They are inherently suitable for dual-polarization signals and insensitive to CD, PMD and fiber nonlinear effect (NLE) [18].…”

Section: Introductionmentioning

confidence: 99%

A Robust Reference Optical Spectrum Based in-Band OSNR Monitoring Method Suitable for Flexible Optical Networks

Zhong

et al. 2020

The in-band OSNR monitoring methods based on the noise-free reference optical spectrum (ROS) have attracted much attention in the field of optical performance monitoring because they are cost-effective and insensitive to chromatic dispersion and polarization mode dispersion. In this paper, we propose a new ROS based in-band OSNR monitoring method that is robust to the distortions due to non-ideal modulation, the variations of the in-line EDFA gain and the number of filtering elements traversed by the signal. Moreover, this method supports using the standard ROS retrieved by the existing machinelearning technique based optical spectrum identification technique, and thus can remove the need to measure the ROS near the transmitter, which is hard to perform, especially in flexible optical networks. These merits make the method more robust and convenient to use in practice. Extensive numerical simulations are presented to demonstrate the merits of the proposed method with respect to the existing ROS based methods.

Section: Introductionmentioning

confidence: 99%

“…Recently reference optical spectrum (ROS) based in-band OSNR monitoring methods have been intensively studied [11]- [16]. These methods utilize widely-deployed conventional optical spectrum analyzers (OSA) [11] or just simple optical band-pass filters (OBPFs) in combination with optical power meters [14]. They rely on a detailed spectral comparison of the ROS without noise which is measured at or near the transmitter with the one measured at the desired OSNR monitoring point.…”

Section: Introductionmentioning

confidence: 99%

Reference Optical Spectrum Based In-Band OSNR Monitoring Method for EDFA Amplified Multispan Optical Fiber Transmission System With Cascaded Filtering Effect

Yin

et al. 2018

The reference optical spectrum (ROS) based in-band optical signal-to-noiseratio (OSNR) monitoring methods are accurate and inherently robust to fiber chromatic dispersion and polarization mode dispersion. They are also very simple and suitable to be deployed ubiquitously in the transmission system. In this paper, a ROS-based in-band OSNR monitoring method is proposed for erbium doped fiber amplifier (EDFA) amplified multispan dense wavelength division multiplexing systems with cascaded filtering effect (CFE) caused by cascaded add-drop filters or wavelength selective switches. In such systems, the optical signal as well as the optical noise may experience significant CFE making the ROS-based methods proposed before ineffective. The new method solves this problem and performs very well for OSNR in the range of 10-30 dB when the fiber nonlinear effect and nonideal filtering effect are present. The OSNR monitor based on the new method is also more convenient to use as only one-time calibration is required when used at different monitoring locations along the optical link.