亚皮秒级时间分辨率的光取样示波器实验样机

利用自行开发的高稳定、低抖动和重复频率可调的“σ”型被动锁模光纤激光器作为高性能光学取样源，与待测的80 Gb/s光脉冲信号同时输入到100 m高非线性光纤中，通过四波混频效应实现了对被测光信号的全光采样。然后利用自行开发的数字信号处理与计算机图形显示软件，精确地重现了被测试的基于RZ码型的80 Gb/s光脉冲信号波形图。同时，还利用该光学取样示波器实验样机系统对重复频率为10 GHz、脉宽为1.8 ps的商用半导体主动锁模激光器的输出波形进行测量，所显示的脉冲宽度值为2.0 ps。这表明开发出的实验样机系统的时间分辨率优于900 fs。

Prototype of an Optical Sampling Oscilloscope with Subpicosecond Temporal Resolution

Low timing-jitter, “σ”-type passively mode-locked fiber laser is used as a high-performance optical sampling pulse source, of which the operation stability is high and the repetition frequency is tunable. Then the generated sequence of ultrashort optical sampling pulses is launched together with a 80 Gb/s optical pulse signal under test into a 100 m-long highly nonlinear fiber (HNLF). The all-optical sampling of an optical signal under test is realized by utilizing the four-wave mixing (FWM) in a HNLF. Consequently, the waveform of a 80 Gb/s optical pulse signal with RZ format is precisely reproduced by a computer and is displayed on its screen by employing our developed software for digital signal processing and computer image processing, respectively. Moreover, the optical sampling oscilloscope prototype is used to measure the pulse waveform and pulse width at the output of a commercially available, actively mode-locked semiconductor laser which produces optical pulses of 1.8 ps width (measured by an autocorrelator) at the 10 GHz repetition frequency. In the experiment, the pulse width measured by this oscilloscope prototype system is 2.0 ps. It is clearly shown that our developed optical sampling oscilloscope prototype has a temporal resolution better than 900 fs.