采用外调制方式得到了重复频率为５ＧＨｚ的非归零码光脉冲。采用二次谐波强度自相关法测量了光脉冲。对实验中的关键技术进行了理论和实验研究。 By using the external modulation, a non-return zero optical pulse with a repetition frequency of 5GHz was obtained. The optical pulse was measured by the second harmonic intensity autocorrelation method. The key technologies in the experiment are studied theoretically and experimentally.