超广角大工作面f-theta镜头的光学设计

Optical design of super wide angle f-theta lens with large operation area

目前国内用于激光标刻机的f-theta镜头的视场角一般小于60°。采用望远镜结构,利用视觉放大率增大视场角,得到了超广角90°镜头。该方法具有简洁、可靠、易实现等特点。通过初级像差分析,确定系统的初级结构参数,利用ZEMAX软件优化得到了大工作面为285mm的f-theta镜头,镜头线性畸变误差值不超过1%,在半径为698μm的圆内,能量集中度为80%,聚焦性能接近衍射极限。

The field angle of f-theta lens used in laser marking system is generally less than 60°.By adopting a telescope structure and using a method of visual magnification,a super wide lens with the field angle of 90°was obtained in the optical system.The method is simple,reliable,and easy to achieve.Based on the analysis of primary aberrations,the parameters of initial structure were determined,and the f-theta lens with a large working area of 285 mm in diameter was obtained by optimizing the initial structure with ZEMAX.The linear distortion error of the lens is less than 1%,the energy concentration rate is 80% in the circle with a radius of 698 μm and the focusing performance is diffraction-limited.