非球面光学元件绝对面形检测技术研究
文献类型：学位论文
| 作者 | 马啸 |
| 文献子类 | 硕士 |
| 导师 | 刘世杰 |
| 关键词 | 非球面光学元件 aspheric optics 液晶空间光调制器 liquid crystal spatial light modulator 物理光学传播 physical optics propagation 波面优化 wavefront optimization 绝对检测 absolute test |
| 其他题名 | Study on Absolute testing of Aspheric surfaces |
| 英文摘要 | 非球面光学元件可以提高光学系统的光学性能并减轻系统重量，使得高性能、高集成的光机电系统成为可能，被广泛应用于航空航天、国防军工及高科技民用领域。随着一大批以计算机数控加工为基础的加工方法不断涌现，非球面加工在加工效率、精度等方面相对于传统加工方法产生了巨大飞跃。高精度的非球面检测技术成为进一步提升非球面加工元件性能的关键。发展实时、通用、自适应的非球面检测技术对提高非球面加工技术、拓展非球面应用具有重要的意义。 高精度非球面检测主要采用零位干涉检测法。然而，零位干涉检测法需要高精度的零位补偿器，且补偿器与非球面一一对应，因此一般的零位检测法成本高、通用性差。此外，一般的零位干涉检测法的面形检测结果中引入了参考波面的误差，降低了检测精度。本文研究了一种基于液晶空间光调制器的非球面面形绝对检测法。液晶空间光调制器在驱动电压控制下可实时、灵活地调制入射光波的波前相位分布，可以用作通用型补偿器应用于各类非球面元件的零位检测中。通过基于N位旋转的平面绝对检测方法，标定出TF镜和RF镜绝对面形；通过绝对检测方式标定液晶空间光调制器绝对相位调制量；从相对检测结果中去除TF镜面形误差以及参考波面误差，从而可实现非球面面形绝对检测。具体工作如下： 调研了纯相位型液晶空间光调制器工作原理、结构特征、及其编码方法。液晶空间光调制器综合利用了液晶的力学性质、电学性质以及光学性质，实现电信号对光场分布的调制；液晶空间光调制器是由许多像素单元组成的空间阵列，理想情况下，各像素单元独立工作，互不干扰；此外，各像素之间存在不透光的栅极，称之为“黑栅”；使用液晶空间光调制器时，采用量化编码方法编写灰度图。 编写基于惠更斯-菲涅尔原理的物理光学传播算法，模拟分析了液晶空间光调制器波面调制的全过程，主要包括检测光波入射到液晶空间光调制器、液晶空间光调制器调制检测光波以及被调制后检测光波传播到待测元件表面。得到液晶空间光调制器像素尺寸、黑栅结构、灰度等级等结构因素对生成波面精度的影响，为选购合适的液晶空间光调制器用于非球面光学元件面形检测提供指导。 分析了液晶空间光调制器制造工艺缺陷、液晶材料缺陷等因素对相位调制精度的影响。根据液晶空间光调制器的实际相位调制量测量结果，提出了一种适用于非球面检测的空间光调制器相位调制优化新方法，可获得更高的相位调制精度。 以一个半径为175mm的凸球面透镜为例，设计并验证了基于液晶空间光调制器为补偿器的相对检测方案和绝对检测方案。相对检测实验结果表明：检测重复性较好，可以采用LC-SLM作为相位补偿器实现非球面零位检测；检测结果误差较大，主要来自于LC-SLM相位调制误差。绝对检测实验结果表明:本文提出的绝对检测方案目前没有明显的精度提升效果，主要是因为目前的LC-SLM相位调制优化并不完善。; Aspheric optical components, which can improve the optical performance of the optical system and reduce the weight of the system, making high-performance, highly integrated optical electromechanical systems possible, are widely used in aerospace, defense and military and high-tech civilian areas. With a large number of computer-controlled CNC machining-based manufacture methods constantly emerging, aspheric surface manufacture have made great process in the efficiency, accuracy and other aspects. High-precision aspheric surface test technology has become the main factor that restricts aspheric surface manufacture. The development of real-time, general-purpose, adaptive aspheric testing technology is of great significance to improve the aspheric processing technology and expand the aspheric surface application. High-precision aspheric test methods are mainly based on null interferometric test. However, null interferometric method requires one unique high-precision null optics for one asphere, and this method is less versatile and high cost. In addition, the error of the reference wavefront is introduced in the general null interferometric test. In this paper, an absolute test method of aspheric surfaces based on the liquid crystal spatial light modulator is proposed. The liquid crystal spatial light modulator can modulate the wavefront phase distribution of the incident wave under the control of the driving voltage, and can be used as a compensator in the null interferometric test. Through the absolute test method based on N-bit rotation measurement, the TF and RF mirror absolute surface are achieved; the absolute phase modulation of liquid crystal spatial light modulator is calibrated by an absolute test method; the TF mirror surface error and the reference wavefront error are removed from the relative test result and an absolute test can be performed. Specific work is as follows: The working principle, structural characteristics and coding method of phase- only liquid crystal spatial light modulator are studied. The liquid crystal spatial light modulator utilizes the mechanical properties, electrical properties and optical properties of the liquid crystal to realize the modulation of the optical field. The liquid crystal spatial light modulator is a spatial array composed of many pixel units. Ideally, each pixel unit performs independently. In addition, there is a 2D black-matrix between the pixels. The quantitative coding method is used to achieve phase modulation. By the physical optical propagation algorithm based on Huygens-Fresnel principle, the compensation process of liquid crystal spatial light modulator is simulated. The influence of the structural factors such as pixel pitch, black matrix structure and gray level on the accuracy of the generated wavefront is obtained by simulation calculation. The simulation work provides guidance for purchase of suitable liquid crystal spatial light modulators for the aspheric surfaces test. The influence of manufacturing defects and liquid crystal material defects on the accuracy of phase modulation is analyzed theoretically. In order to improve the accuracy of the generated wavefront, a phase modulation optimization method for spatial light modulator is proposed. This optimization method realizes the optimization for the full aperture and full gray scale of the spatial light modulator. The test was carried out with a convex spherical lens with a radius of 175 mm. The relative test scheme and absolute test scheme based on liquid crystal spatial light modulator as compensator are designed and verified. Relative test results show that: detection repeatability is good, and the LC-SLM can be used as a phase compensator to conduct aspheric null interferometric test; the test error is large mainly because of the LC-SLM phase modulation error. Absolute test results show that: the absolute test scheme shows no obvious improvement in the test accuracy at present, mainly because the current LC-SLM phase modulation optimization is not perfect. |
| 学科主题 | 材料学 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/30956]  |
| 专题 | 中国科学院上海光学精密机械研究所 |
| 作者单位 | 中国科学院上海光学精密机械研究所 |
| 推荐引用方式 GB/T 7714 | 马啸. 非球面光学元件绝对面形检测技术研究[D]. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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