瞬态宽带宽光信号广泛存在于激光干涉测速、光通信等领域, 具有宽带宽、非重复性的特点, 但现有的直接或间接光脉冲测量技术还无法应用于此类信号的测量。利用时间-波长映射的啁啾光脉冲和四波混频效应对瞬态光信号进行超高速光采样, 通过采用时间拉伸技术和色散介质, 放大其时间尺度, 成倍提高了后端电子记录系统的带宽及采样率。实验结果表明, 该方法可以实时测量带宽为56.978 GHz的光拍频信号, 等效测量时间分辨率为3.7 ps, 证实了所提方法的有效性。

The transient optical signal with wide bandwidth widely exists in laser interference velocity measurement, optical communication and some other fields. It has wide bandwidth and non-repeatability. The existing direct or indirect optical pulse measurement technologies cannot be applied to the measurement of such signal. We use time-wavelength mapping chirped optical pulse to sample the transient optical signal at a high rate under the four wavelength mixing effect, and magnify the signal time scale by using time-stretching technology and dispersive medium. The bandwidth and sampling rate of the back-end electrical record system are increased by times. The experimental results show that the measurement of light beat-frequency signal with bandwidth of 56.978 GHz in real-time is feasible and the equivalent measurement time resolution is 3.7 ps, which verifies the validity of the proposed method.