随着光纤耦合激光器的应用需求不断增大,对光纤与激光器的耦合效率要求也随之增大。不同波长激光的聚焦点位置存在差异, 激光聚焦点位置是影响耦合效率的重要因素之一,对激光聚焦点的精准定位具有一定的实用性。设计一个聚焦组合透镜组聚焦激光器光束,采用CCD相机采集激光聚焦点焦前、 焦后位置图像,通过MATLAB软件处理采集的图像,圆拟合光斑并计算光斑直径,直径最小位置即是聚焦点位置。结果表明,不同波长激光聚焦点位置不同且焦距相对误差分别 为0.59%和0.73%,测量的焦点位置和大小均可精确到0.001 mm。该方法设计简单,具有自动性和精确性,对不可见激光聚焦位置的判断更显优越。

With the increasing demand for the application of fiber coupled laser, the requirement for the coupling efficiency of fiber optic and laser laso increases. The positions of the focusing spots of laser with different wavelength are different. The position of the laser focusing spot is one of the important factors affecting the coupling efficiency, and it has certain practicability for the precise positioning of the laser focusing spot. A focusing combined lens group is designed to focus laser beam. The CCD camera is used to collect the images of the front and back laser focusing points. The acquired images are processed by MATLAB software, where the spot is fitted by circle and the diameter of which is calculated. The position of the minimum diameter is the focus position. The results show that the laser focus position with different wavelength is different and the relative errors of focal length are 0.59% and 0.73%, both the measured focus position and the size can be accurate to 0.001 mm. The method has the advantages of simple design, automaticity and accuracy, and especially in judging the focus position of the invisible laser.