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Meter-level aspheric mirrors are the core optical products in space optical remote sensors. With the development of space optical remote sensing technology, the mirror manufacturing quality have gradually evolved from focusing on some key parameters in the past to global control of full index parameters. This is undoubtedly bringing great challenges for optical fabrication and testing. Taking a typical meter-level aspheric mirror as an example, the article introduces a full-parameter process control method for aspheric mirrors for space applications. First of all, in the aspheric surface shape milling and grinding stage, the contour measurement method is used to initially control the radius of curvature of the mirror surface, the aspherical surface coefficient, the effective aperture and the deviation of the optical axis; secondly, after entering the rough polishing stage, the mirror surface is quickly improved at the same time as the roughness index of the mirror, it improves the accuracy of the mirror surface shape and controls the mid-to-high frequency error. Finally, in the fine polishing stage, the method of gravity unloading is used to acquire the zero-gravity surface shape of the space mirror. The geometric and optical parameters of the mirror converge to the expected value, of which the error of the vertex curvature radius is better than 0.5mm; the error of the aspherical coefficient is better than 0.01%; the deviation of the optical axis is better than 1′/ 1mm, and the rms of the surface shape accuracy in the whole frequency band is better than 10nm, the low-band error is better than 8nm, and the mid-band error is better than 3nm; the surface roughness rms is better than 1nm, and the remaining parameters meet the needs of camera on-track applications. The proposed process control method has been expanded and can also be applied to high-precision manufacturing of aspheric mirrors in the range of 1-4m.

介绍了 Ф 420 mm熔石英高次非球面透镜的加工与检测方法。对现有数控加工工艺进行了优化，通过分工序加工方式，依次采用机器人研磨、抛光和离子束修形技术完成了透镜的加工。进行非球面透镜检测时，考虑透镜的凹面为球面，利用球面波干涉仪对其面形进行了直接检测，剔除干涉仪标准镜镜头参考面误差后，透镜凹面的精度达到0.011λ-RMS；针对透镜的凸面为高次非球面，采用基于背后反射自准法的零位补偿技术对其进行面形检测，其精度达到0.013λ-RMS。最后，采用一块高精度标准球面镜对加工后透镜的透射波前进行了自消球差检测，得到其波前误差为0.013λ-RMS。试验结果表明，非球面透镜各项技术指标均满足设计要求。所述工艺方法亦适用于更大口径的非球面透镜及其他类型非球面光学元件的高精度加工.

Base on the special characters of off-axis spherical and three-axis ion beam figuring (IBF) system, a method of obtaining the removal function depending on incidence angles are introduced and the curve be indicated. Keeping the fabrication coordinate coincident to the optical coordinate can avoid the transformation of interferometry map, which could introduce the distortion error. By analyzing of the process of polishing the 562mm×290mm off-axis mirror, the polishing experimentation has been carried out on the IBF2000 system developed by NTG. After two iterations and 37.2 hours polishing time, the RMS value of surface accuracy is from 0.033λ to 0.016λ, and the mid-spatial error mitigated dramatically. The experimentation indicates that using the non-contacting polishing feature of IBF with reasonable optimizing process, the surface accuracy and the mid-spatial error can be improved simultaneously.

By using the method of computer modeling with Matlab to compute the coordinate values of discrete points of the ideal collimating lens,the parameters of cylindrical lens are solved through the method of numerical fitting and quadric surface approximation,which simplifies the design process of laser diode beam collimated by cylindrical lens and facilitates the actual operation.The analysis result shows that the cylindrical lens with quadric surface are very suitable for collimating laser diode beam,and whose surface can be selected by actual requirements.By contrast,this method is simple,and it can easily be designed,and which can quickly adjusts the parameters to optimize.At the same time,the parameters of collimating lens can be properly selected by the grade of difficulty level in the manufacture process.

为了满足空间同轴三反相机对大口径凸非球面高精度的面形质量和精确的几何参数控制要求，提出以计算机控制确定性研抛工艺为核心的多工序组合加工及检测技术。在加工阶段，首先利用超声振动磨削技术对非球面进行面形铣磨，其次应用机器人对非球面面形进行快速研磨和粗抛，最后采用离子束修形技术实现非球面的高精度加工；在检测阶段，首先利用三坐标测量机对铣磨和研磨过程中非球面的面形及几何参数进行控制，进入干涉仪测量范围后，再采用Hindle球法对非球面光学参数进行干涉检测。结合工程实例，对一口径520 mm的凸双曲面次镜进行了加工及检测，其面形精度RMS为0.015（=632.8 nm），几何参数控制精度△R误差为0.1 mm、△K优于0.1%，满足光学设计技术指标要求。

Minimum variance (MV) adaptive beamforming has been applied in medical ultrasound imaging to improve lateral resolution, but standard MV method is quite sensitive to the perturbation of the received signal. Due to the inhomogeneity of human tissues, sound speed varies and there exists a certain amount of time-delay error for each channel which is referred to as phase aberration. A robust minimum variance adaptive beamforming method was proposed in order to avoid significant degradation under more practical circumstances. The sample covariance matrix was reconstructed with a forward-backward method. And the steering vector was estimated via maximizing the output beamformer power, which was turned into a quadratic convex optimization problem with proper constraints. The simulations with Field II showed that the proposed method was robust in the presence of phase aberration and could maintain its performance for improving imaging quality.

Metal is an early telescope mirror material, it was later replaced by glass which has lower thermal expansion coefficient. However, for observing the sun, these glass materials in the primary mirror are affected by the sun's intense radiation, its temperature rises rapidly, but which conducts heat slowly. The temperature difference between mirror and ambient air is so large that causing the air turbulence which has affected the observation precision. While the metal material has better thermal conductivity characteristics, it can greatly improve the problems caused by air turbulence. This paper analyzes the characteristics of the various mirror materials, and then makes a rust-proof aluminum alloy 5A05 as the mirror substrate material. For the major deficiencies of the soft aluminum surface which is not suitable for polishing, this paper presents a method of electroless nickel plating to improve its surface properties. After the mirror go through a thermal shock, the upper and lower levels of metal CTE don’t match with each other, which leads to mirror deformation and warping. The bimetallic effect has been illustrated by the theory of beam element and give a result of elementary approximated. The analysis shows that the displacement deformation of the upper and lower layers of metal which is caused by thermal shock is smaller when the CTE is closer. In the experiments, a spherical aluminum mirrors with the substrate of 5A05 aluminum alloy, diameter of 110mm, the radius of curvature of 258.672mm is manufactured in classical technique. And it ultimately achieves optical mirror-polished precision. Besides, the long-term thermal stability experimental study of the aluminum mirrors proved that Al-infrared solar telescope primary mirror meets the needs of the long-term observation during use.