衍射光学元件以其优异的光学性能,能够调制出理想的波面,较球面、非球面光学系统在校正色差方面具有较大优势。衍射光学元件的加工难点在于其加工精度不仅要求非球面基底的面形满足精度要求,还需要衍射结构的相位突变点及高度满足要求。由于其面形非连续性,存在相位突变点,传统的检测方式难于满足要求。对轮廓仪检测误差来源进行分析,结合检测数据分析加工误差数据,在此基础上进行数据处理,并将该方法获得的误差数据应用于零件加工,实现口径120 mm衍射面加工面形误差为0.539 μm。

Diffractive optical elements (DOEs) , with their excellent optical properties, can modulate the ideal wavefront, and have greater advantages in correcting chromatic aberration than spherical or aspherical optical systems.The difficulty in the processing of DOE lies in the fact that its processing accuracy requires not only that the surface shape of the aspherical substrate satisfies the accuracy requirements, but also that the phase saltation position and the height of the diffractive structure satisfy the requirements.Due to the discontinuity of the surface and the phase saltation position, the traditional detection method is difficult to meet the requirements.The detection error source of the profiler was analyzed, and the machining error data was analyzed in combination with the detection data. Based on this, the data processing was performed. The error data obtained by this method was applied to the part processing, and the surface shape error of the 120 mm diffractive surface was 0.539 μm.