激光光束质量M^2因子测量系统的设计

Design of the Measurement System for Laser Beam Quality M^2 Factor

为了实现对激光器发射激光光束质量的自动化测量,提出了一种激光光束质量M2因子测量系统。该系统选择混合式步进电机作为执行机构来确定多个采样位置;同时系统采用面阵电荷耦合器件(CCD)多点探测激光光斑的图像信息,实时计算不同采样位置激光光斑的质心和光强,并根据M2因子理论计算出激光光束的束腰宽度和束散角等参数,最后由上位机显示激光光斑的二维/三维光强分布及处理结果。实验结果表明,系统能够对400～1 100 nm连续激光器发射激光光束质量进行自动化测量,测量精度达±6%,测量时间小于3 min。

In order to realize automatic measurement of beam quality emitted by laser,the measuring system of laser beam quality factor M2 is proposed.In this system,hybrid stepping motor is selected as actuator for determining multiple sampling positions.In addition,the image information of the laser spots at multiple positions is detected by using array charge couple device（CCD）,and the centroid and light intensity of dif-ferent sampling positions are calculated in real time,then the parameters,such as beam waist width and divergence angle,etc.,are calculated theoretically in accordance with M2 factor,finally the 2D/3D distribution of light intensity and processing result are displayed on the host computer.The result of experiment indicates that the system can automatically measure the laser beam quality for 400～1100 nm continuous laser,the measuring accuracy is up to ± 6%,and the measuring time is less than 3 min.