飞秒激光系统图像调焦装置以及方法  

An Image Focusing Device and Method for Femtosecond Laser System

作　　者：寇千慧 刘华[1] 谭明月 陆子凤[1] 张有旋 王雨时 KOU Qianhui;LIU Hua;TAN Mingyue;LU Zifeng;ZHANG Youxuan;WANG Yushi(Advanced Optoelectronie Functional Materials Research Center,Key Laboratory of Ultraviolet Emitting Materials and Technology of Ministry of Education.Northeast Normal University,Changchun,Jilin,130024;Beijing Institute of Control Engineering.Beijing 100190,China)

机构地区：[1]东北师范大学先进光电子功能材料研究中心、紫外光发射材料与技术教育部重点实验室,长春吉林130024 [2]北京控制工程研究所,北京100190

出　　处：《空间控制技术与应用》2020年第6期37-42,共6页Aerospace Control and Application

基　　金：国家自然科学基金资助项目(61875036)。

摘　　要：飞秒激光直写技术在复杂三维微结构加工领域具有显著优势,而调焦是否精准直接影响了所加工结构的完整度.提出了在光路中临时置入调焦光源和物的图像调焦技术,通过调节物的位置使其成像面与激光聚焦面一致,从而通过清晰可分辨的成像状态间接反映激光聚焦状态.利用Zemax软件模拟分析了原飞秒激光光路与加入调焦光源和物的调焦光路,二者可实现相同加工物镜后工作距离与良好成像质量,证明了该方法的可行性.通过分析得到该过程的成像误差主要由成像镜头焦深(3.9μm)引起,我们获得的理想调焦精度可达到1/2焦深以内.设计了单层高度为5μm的二层圆柱结构,通过多次实验验证了所加工元件高度误差在1.5μm范围以内,与理论分析一致,满足飞秒激光系统的调焦要求.Femtosecond laser direct writing technology has significant advantages in the field of complex three-dimensional microstructure processing,and the accuracy of the focusing directly affects the integrity of the processed structure. This paper presents an image focusing technique in which light source and object are temporarily placed in the optical path. By adjusting the position of the object,the imaging plane is consistent with the laser focusing plane,so that the laser focusing state can be indirectly reflected by the clear and resolvable imaging state. The Zemax software is used to simulate the processing optical path and the focusing optical path respectively. The results show that the two kinds of simulation results can achieve the same back working distance and good imaging quality,which proves the feasibility of the method. The analysis shows that the imaging error of this process is mainly caused by the focal depth of the imaging lens( 3. 9 μm),and the ideal focusing accuracy can reach within 1/2 focal depth. A two-layer cylindrical structure with a single-layer height of 5μm is designed for testing. It is verified through multiple experiments that the height error of the processed components is within the range 1. 5 μm,which is consistent with the theoretical analysis and meets the focus requirements of the femtosecond laser system.

关 键 词：飞秒激光直写系统 调焦技术 光学设计 模拟分析 加工精度 

分 类 号：O43[机械工程—光学工程]