Effect of the measuring mirror surface shape error on ruled groove straightness and the grating diffraction wavefront

2020 ◽  
Vol 59 (27) ◽  
pp. 8465
Author(s):  
Xiaotao Mi ◽  
Shanwen Zhang ◽  
Xiangdong Qi ◽  
Haili Yu ◽  
Hongzhu Yu ◽  
...  
Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7993
Author(s):  
Meijun Zhang ◽  
Qipeng Lu ◽  
Haonan Tian ◽  
Dejiang Wang ◽  
Cheng Chen ◽  
...  

In order to improve the image quality of the aerial optoelectronic sensor over a wide range of temperature changes, high thermal adaptability of the primary mirror as the critical components is considered. Integrated optomechanical analysis and optimization for mounting primary mirrors are carried out. The mirror surface shape error caused by uniform temperature decrease was treated as the objective function, and the fundamental frequency of the mirror assembly and the surface shape error caused by gravity parallel or vertical to the optical axis are taken as the constraints. A detailed size optimization is conducted to optimize its dimension parameters. Sensitivities of the optical system performance with respect to the size parameters are further evaluated. The configuration of the primary mirror and the flexure are obtained. The simulated optimization results show that the size parameters differently affect the optical performance and which factors are the key. The mirror surface shape error under 30 °C uniform temperature decrease effectively decreased from 26.5 nm to 11.6 nm, despite the weight of the primary mirror assembly increases by 0.3 kg. Compared to the initial design, the value of the system’s modulation transfer function (0° field angle) is improved from 0.15 to 0.21. Namely, the optical performance of the camera under thermal load has been enhanced and thermal adaptability of the primary mirror has been obviously reinforced after optimization. Based on the optimized results, a prototype of the primary mirror assembly is manufactured and assembled. A ground thermal test was conducted to verify difference in imaging quality at room and low temperature, respectively. The image quality of the camera meets the requirements of the index despite degrading.


2021 ◽  
Vol 346 ◽  
pp. 03074
Author(s):  
Aleksandr Grechukhin ◽  
Vadim Kuts

The paper presents the results of a study of the process of additive surface shaping by an electric arc in a protective gas. An analysis was made of the errors in the shape of surfaces obtained with different filling of layers. It has been experimentally confirmed that such process parameters as the orientation of the layers, the coefficient of their overlap are significant and affect the numerical value of the error in the shape of the resulting surface. In this connection, they should be taken into account when designing algorithms for dividing into layers and filling them with additive shaping by an electric arc in a protective gas.


Author(s):  
Azhar Iqbal ◽  
Foued Ben Amara

Magnetic fluid deformable mirrors (MFDMs) present a simple alternative to the expensive and delicate wavefront correctors currently in use in adaptive optics (AO) systems. Such mirrors are particularly suitable for retinal imaging AO systems. The practical implementation of a retinal imaging AO system incorporating a MFDM requires an effective control system to control the shape of the mirror surface. The real-time control of the mirror surface requires a model of the mirror that can be used to determine the dynamic response of the mirror to a magnetic field applied as the control input. This paper presents such a model that not only determines the dynamic response of the MFDM but also takes into account the unique requirements of the retinal imaging application of the mirrors. The mirror is modeled as a horizontal layer of a magnetic fluid. The dynamic response of the mirror to the applied magnetic field is represented by the deflection of the free surface of the layer. The surface deflection is determined by the modal analysis of the coupled fluid-magnetic system. Considering the requirements of the retinal imaging application, the effects of surface tension and depth of the fluid layer are duly represented in the model. The mirror model is described in a state-space form and can be readily used in the design of a controller to regulate the mirror surface shape.


2021 ◽  
Author(s):  
Bowen Xu ◽  
Shanshan Wang ◽  
Ci Song ◽  
Yinlong Hou ◽  
Feng Shi ◽  
...  

2016 ◽  
Vol 43 (4) ◽  
pp. 0416003
Author(s):  
吕亮 Lü Liang ◽  
马平 Ma Ping ◽  
朱衡 Zhu Heng ◽  
黄金勇 Huang Jinyong ◽  
王刚 Wang Gang

2014 ◽  
Vol 937 ◽  
pp. 396-399
Author(s):  
Chun Min Shang ◽  
Dong Mei Zhang ◽  
Xin Ming Zhang

An analyzing rotating error method has presented based on grinding aspheric optical component. A coordinate transform has been done between the new and original coordinates system in view of the rotating error in installing parts, further, the rotating angle error model has deduced between actual curve and theoretical curve. The surface error formulas can be used for variety of rotary conic aspheric curve, depending on the requirements of the parts surface accuracy, quantitative adjustment target can be given in installation and adjustment process before grinding. Based on the rotating error formulas, the calculating example shows that installation angle bas various different influence to surface shape error, the error decreases with the θ decreasing, the surface error is reduced a magnitude accordingly when the angle is reduced to a magnitude. The parts surface error is up from-0.0030mm to-0.0448mm when the rotating angle increasing from 0.1° to 1°. When θ is constant, the surface shape error increases with steepness increasing, installing rotating angle requirement is more stringent for all the large steepness parts.


2010 ◽  
Vol 102-104 ◽  
pp. 750-753
Author(s):  
Zheng Min Yang ◽  
Hong Ping Hu ◽  
Yu Bin Gao

Magnetorheological finishing technology is a new generation of high-precision optical accessory polishing and processing methods. It presents a MRF dwell time algorithm that can quickly calculate the resident time during magnetorheological processing of the rotational optical parts. A magnetorheological forming polishing experiment on a prototype has been carried out on BK9 glass parts of 20mm rotary symmetrical face shape. The algorithm can improve the surface shape precision of the workpiece from 6.5um to 0.61um. Emulational and experimental results show that the surface shape error of a spherical polished workpiece is convergent by this method, which is also, applies to magneto-rheological finishing of non-spherical and planar workpiece.


2015 ◽  
Vol 1089 ◽  
pp. 309-314
Author(s):  
Xiu Hua Fu ◽  
Yang Liu ◽  
Zong He Jia

For the aspheric processing is complex , time consuming and difficult to guarantte the eccentricity ,this paper introduce a new method of aspheric processing --repairing and polishing methed and describe the principle . Best fit radius, removal function were computed by mathematical model method and the respective performance curves were given by simulation. This methed has the particular advantage of shortening the working time ,reducing the eccentric amount of the element and improving the processing efficiency. Through this processing method, do a series of processing experiments on the smaller aspheric tolerance single crystal silicon aspheric.As the result indicated , plane surface shape error PV 0.52 μm,surface roughness RMS value of single-crystal silicon 0.09 μm ,the center deviation was less than1μm and the surface smoothness meet the standard above the grade Π.


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