面对100 Gb/s光纤传输系统性能监测需求，自主研制完成高速线性光采样模拟前端。其内部由1个被动锁模光纤激光器产生脉宽为2 ps、重复频率为96.25 MHz 的采样光脉冲，待测偏振复用四相移键控(PDM-QPSK)信号和采样光脉冲进入光混频器后完成偏振相位分集探测，利用模拟带宽为400 MHz的平衡探测器完成光电转换后，将4路模拟信号传入主机进行数字化处理，获得高速光信号时域分析结果。通过优化设计，实现被动锁模光纤激光器的脉冲功率、中心波长、重复频率稳定输出。利用商用128 Gb/s PDM-QPSK 信号对工程样机和安捷伦调制信号分析仪N4391A 展开对比测试，测试结果表明工程样机可获得相同的时域参数分析结果。

A temporal signal measurement equipment for current 100 Gb/s fiber optic transmission, based on the linear optical sampling technique, is proposed and experimentally demonstrated. In the self-developed prototype, a passively mode-locked fiber laser is used as optical sampling source with a pulsewidth of 2 ps and repetition frequency of 96.25 MHz. Then, the polarization division multiplexing quadrature phaseshift keying (PDM-QPSK) signal under test is optically mixed with the sampling pulse before phase and polarization diversity detection. With the help of four-channel 400 MHz balanced photodetectors, four-channel analog signals are transmitted to the mainframe, for the purpose of digital signal processing and result display. By optimizing the design, pulse power, central wavelength, repetition frequency of passively mode-locked fiber laser can be output stably. Furthermore, the performance comparison with the counterpart from Agilent modulation format analyzer (N4391A) is carried out, and it’s verified that the prototype has almost the same capability for on-site measurement.