Experimental Evaluation of Optical Signal-to-Noise Ratio Measurement in Coherent Communication Systems
Аннотация
In this article, the author has detailed the challenges and the current developments in the measurement of the Optical Signal-to-Noise Ratio (OSNR) in the high-speed coherent optical communication systems based on polarization multiplexing (Pol-Mux). Measurement of Optical Signal-to-Noise Ratio (OSNR) is now an urgent problem in contemporary coherent optical communication systems with high speed (e.g. polarization multiplexing (Pol-Mux)). The recent trends of tight channel separation, strong spectral filtering and complex modulation schemes at frequencies up to 400 Gbps mean that conventional OSNR measurement methods based on out of band spectral analysis are no more. The study will overcome these shortcomings by experimentally testing the operation of Viavi Pol-Mux OSA-710 a modern optical spectrum analyzer that employs Spectral Correlation Method (SCorM). The suggested solution allows to measure the in-band OSNR correctly, without disruption of the service delivery, independent of the dispersion impairments and modulation format. It has been experimentally shown that the SCorM-based OSNR estimation is precise within a range of ±0.5 dB with regard to conventional OSA methods, and stable under the conditions of different polarizations and filtering. Their results support the Pol-Mux OSA-710 as an effective and stable solution to the real-time OSNR monitoring of the coherent DWDM systems, enhancing the quality of the network performance measurement and lowering the cost of the operational process of the installation and maintenance phases.