高速光纤通信测量技术的发展趋势

 光纤通信单信道速率持续向100 Gbit/s甚至更高发展，对测量仪器的带宽提出了更高的要求。由于电子瓶颈的限制，传统的电示波器极限带宽在70～90 GHz。目前能够测量100 Gbit/s光通信信号的电示波器技术难度和成本越来越高。为了突破电子瓶颈的限制，需要采用新的采样机理对超高速光通信信号或超宽带光信号进行测量。介绍了光域采样的基本原理和相应的光采样示波器及光采样示波器研发的进展。随着信道速率的不断提高，光纤链路的物理损伤对信号的影响越来越显著，如何监测光纤链路的物理损伤成为超高速光通信网需要解决的问题。基于对光物理层损伤的研究，提出了采用分数阶傅里叶变换测量光纤链路色散和非线性效应的方法，并对高速光纤通信链路的测量技术发展作了展望。

Technology development trend for high speed optical fiber communication measurement

Single channel rate for optical fiber communication has been up to 100 Gbit or even higher, thus a higher and higher bandwidth of the measuring instrument is required. Due to the limitation of electronic bottleneck, the bandwidth limit is 70~90 GHz. At present, difficulty and cost for an electric oscilloscope to be able to measure 100 Gbit/s optical communication signals are increasing. In order to break through the limitation of electronic bottleneck, some new sampling mechanism is needed to measure the ultra high speed optical communication signal or the ultra wide band optical signal. This paper introduces the basic principle of optical field sampling and the corresponding optical sampling oscilloscope that has the advantages of high time precision and ultra wide band measurement. Also introduced are the development progresses of optical sampling oscilloscope made by the authors' research group and foriegn counterparts. In addition, with continuous improvement on channel rate, the influence of physical damage of optical fiber link on signal is becoming more significant. Therefore, how to monitor physical damage turns to be a problem in the ultra high speed optical communication network. A method of measuring the dispersion and nonlinear effect of optical fiber link based on fractional Fourier transform is presented. In the end, the development of measurement technology for high speed optical fiber communication link is prospected.