提出了一种基于自聚焦透镜耦合单模光纤测量调频小宽带脉冲时间波形的技术方案。理论分析和实验结果表明:自聚焦透镜耦合光纤的取样能量随透镜与光束夹角增大而减小，但同一角度下各级次光谱耦合效率一致，取样过程不会引入附加的调频-调幅(FM-AM)效应，耦合效率下降一半时允许的光束角漂量为1 mrad。该技术方案除具有便于集成、低成本、抗光束扰动能力和电磁干扰能力强等优点外，还通过自聚焦透镜扩大了取样面积，有效提高了取样能量，并抑制了光束截面能量起伏对测量系统的不良影响。该技术方案为高功率激光装置脉冲波形测量技术的改进研究提供了一定的理论和实验基础。

In this paper, a pulse temporal profile measurement scheme based on self-focusing lens coupling of single-mode optical fiber for small broadband frequency modulation pulse is introduced. Theoretical analysis and experimental results show that sampling energy with self-focusing lens coupling fiber decreases with the increase of the angle between lens and beam, but spectrum coupling efficiency of different orders is the same at the same angle. It means that the process of sampling will not introduce additional frequency modulation leading to amplitude modulation (FM-AM) effect. When the coupling efficiency drops in a half, the allowable drift angle of beam is 1 mrad. The technique scheme has advantages such as convenient to integrating, low cost and resistant to beam disturbance and electromagnetic interference. Besides, the sampling area has been expanded through the self-focusing lens that effectively improves the sampling energy and suppresses the adverse impact of beam cross section energy ups and downs on the measurement system. The technical scheme provides a certain theoretical and experimental basis for the improvement research of high power laser facility temporal profile measurement technology.