激光直写凹球面网栅的电控实现

凹球面网栅激光直写系统采用同心结构及稳光控制保证了光强不变,提出了周期纬线纬纬相交形成网栅的图形结构,应用调节角速度的控制算法,确保激光直写光斑在不同的纬度以不同角速度扫描,始终保持线速度和曝光量恒定,实现了在凹球面上以恒定曝光量激光直写网栅。分析了网格周期、角速度和纬线弧长等关键参数,设计了控制程序。在通光孔径60 mm的普通玻璃凹球面进行了多组激光直写试验,设定周期450 mm~800 mm,线速度1 mm /s ~20 mm/s,经显影、定影后由读数显微镜测得网格实际周期与设定周期误差在±3%以内,原子力显微镜测得线宽小于5 mm,线条侧壁陡直、平行,具有较好的均匀性,满足设计要求。

The realization of electric control of laser direct writing mesh on the concave spherical substrate

The concentric configuration and steady light control are adopted in the laser direct writing system for the concave spherical substrate. Without changing angular velocity as the variety of the latitude position of the laser spot, the exposure dose will change also. As a result, the line quality is influenced. The control method and arithmetic of laser direct writing high precision mesh are advanced, which can ensure the linear velocity and the exposure dose invariable by controlling the laser spot scanning at accurate angular velocity in different latitude. The smart and effective method of periodical woofs intersecting periodical woofs forming mesh is advanced also. The control course of laser direct writing mesh is given. And the arithmetic of key parameters, such as the period of gridding, angular velocity and the length of the woof are analyzed. Experiments of laser direct writing mesh on common glass concave spherical substrate, with an aperture equal to 60 mm after twirling coating photoresist, have been conducted. The period settings are from 450 ?m to 800 ?m, and the linear velocity settings are from 1 mm/s to 20 mm/s. After development and fixation, the error of gridding period measured by micron level microscope is within±3%. And the section analysis of lines by the atomic force microscope has proved that the line width is less than 5 ?m, and the steep sides of the lines are parallel to each other. The results of experimentation satisfy the requirements of the design.