Real-Time Eye Diagram Monitoring for Optical Signals Based on Optical Sampling

A real-time eye diagram monitoring method for optical signals is proposed and experimentally demonstrated based on sampling. In the system, under test are directly sampled by an sampling pulse train with a narrow width high repetition frequency. The achieved in Mach-Zehnder modulator (MZM), gated on-off electrical pulse. then broadened detected photodetector (PD). low-speed analog-to-digital converter (ADC) will quantify signals. Combining algorithm infinitesimal calculus, quantified data used to achieve diagram, according which more time-domain parameters, such as period, time jitter, Q value, bit error rate (BER) test, obtained. Thanks of train, parameters observed real time. Experimental results show that about 350-μs 2.5-Gb/s signal dynamic range from −10 −22 dBm achieved. addition, jitters measured 4.3 49.8 ps. values estimated 20.4 4.3, corresponding BERs ranging 2.3 × 10−92 8.5 10−6. also verified commercial oscilloscope.