Research On The Low-cost And Multi-parameter Monitoring Of The Optical Performance Monitoring In Next Optical Network

With the rapid growth of network traffic demand in recent years, ultra-high speed and largecapacity optical transmission system is becoming more important than before. To realize this target system, we use many new technologies such as more advanced modulation format, broader modulation bandwidth and much more variety of multiplexing technologies. But this transmission system needs higher quality requirements of optical fiber link and is more sensitive to all kinds of impairments, so it’s very important to monitor the performance of the optical transmission system in real time. Optical signal-to-noise ratio(OSNR), chromatic dispersion(CD), polarization mode dispersion(PMD) are three most common parameters that affect the transmission quality of optical signal, so it’s important to monitor these parameters to achieve zero bit-error-rate(BER) transmission system.We put forward a novel low-cost coherent scanning optical performance monitoring(OPM) scheme based on the currently existing different researches. This scheme has several features: 1. This scheme is based on low-cost coherent scanning so that it can obtain amplitude, phase and polarization of the narrowband optical signal. Thus it can realize multiple parameters monitoring and it is different from the existing schemes; 2. This scheme can use the same experimental device to achieve multiple parameters monitoring just by using different beating frequencies and digital signal processing(DSP) algorithms; 3. This scheme only uses simple DSP algorithms and it’s easy to realize. And it is not sensitive to other common parameters and has little estimation errors and high applicability. This paper focuses on the research of OSNR and CD monitoring and the major work is as follows.1. We explain the principle of monitoring OSNR and CD in detail, gives the basic way to realize it and derives the relevant formula.2. We simulate the feasibility of this scheme to monitor OSNR and CD by using VPItransmission and MATLAB. The simulation results show that when the OSNR value ranges from 10 d B to 25 d B, the OSNR estimation errors are within ±1d B, and when the CD value ranges from 1280ps/nm to 12800ps/nm, the CD estimation errors are within ±8ps/nm. Besides, we research the relationship of estimation errors and the bandwidth of coherent receiver and CD value on OSNR monitoring. And we study the relationship of CD estimation errors and sampling rate, the bandwidth of coherent receiver and OSNR value.3. We demonstrate an experiment to show this scheme’s practical feasibility. The experimental results show that the OSNR estimation errors are within ±1d B when the OSNR value ranges from 10 d B to 25 d B and the CD estimation errors are within±200ps/nm when the CD value ranges from 404ps/nm to 3232ps/nm. The experimental results are almost the same as the estimation results.