离子束螺旋扫描方式修正光学镜面方法

Ion Beam Figuring Method for Optical Mirrors with Spiral Scan Mode

研究基于螺旋扫描方式的光学镜面离子束修正方法。根据离子束去除函数的特性,将螺旋扫描加工过程简化成线性过程并建立工艺过程模型,采用基于Bayesian原理的改进Richard-Lucy迭代法求解驻留时间。在分析驻留时间的连续速度实现基础上,给出螺旋路径参数的确定准则。建立螺旋扫描加工方式的工艺流程并进行试验验证研究。试验研究对φ100平面镜和φ200非球面镜修形加工得到了面形方均根误差均优于0.01λ。研究结果表明:极轴加工与普通的全口径加工一样是一种高效率、高确定性的加工方法,能够对镜面进行精确修形,同时可以节约加工成本。

The ion beam figuring method for optical mirrors with spiral scan mode is discussed. With the near-Gaussian property of the removal function, the figuring process can be simplified to a linear one and described by conventional computer controlled optics shaping （CCOS） principle. The modified Richard-Lucy iterative algorithm based on the Bayesian principle is adopted for the solution of dwell time. On the basis of analysis of the continuous velocity of dwell time, the criteria for determining the spiral path parameters are given. With these methods, the ion beam figuring technology with spiral s can mode is established. The figuring experiments on planar and aspheric samples are made, the final surface errors are both below 1/100λ The experimental results show that spiral figuring is a deterministic method of high efficiency for optical mirrors, and can be used as the final figuring process, moreover the processing cost can be reduced.