scholarly journals A Design for a Manufacturing-Constrained Off-Axis Four-Mirror Reflective System

2020 ◽  
Vol 10 (15) ◽  
pp. 5387
Author(s):  
Ruoxin Liu ◽  
Zexiao Li ◽  
Yiting Duan ◽  
Fengzhou Fang
Keyword(s):  
Design Method ◽  
Optical Systems ◽  
Initial Structure ◽  
Manufacturing Constraints ◽  
Structural Configuration ◽  
Entrance Pupil ◽  
Good Imaging ◽  
Ultra Precision ◽  
Reflective Systems ◽  
Entrance Pupil Diameter

Off-axis reflective optical systems find wide applications in various industries, but the related manufacturing issues have not been well considered in the design process. This paper proposed a design method for cylindrical reflective systems considering manufacturing constraints to facilitate ultra-precision raster milling. An appropriate index to evaluate manufacturing constraints is established. The optimization solution is implemented for the objective function composed of primary aberration coefficients with weights and constraint conditions of the structural configuration by introducing the genetic algorithm. The four-mirror initial structure with a good imaging quality and a special structural configuration is then obtained. The method’s feasibility is validated by designing an off-axis four-mirror afocal system with an entrance pupil diameter of 170 mm, a field of view of 3° × 3° and a compression ratio of five times. All mirrors in the system are designed to be distributed along a cylinder.

scholarly journals Design of a Variable-Stiffness Compliant Skin for a Morphing Leading Edge

2021 ◽  
Vol 11 (7) ◽  
pp. 3165
Author(s):  
Zhigang Wang ◽  
Yu Yang
Keyword(s):  
Composite Laminate ◽  
Large Scale ◽  
Design Method ◽  
Leading Edge ◽  
Variable Stiffness ◽  
Manufacturing Constraints ◽  
Aircraft Wing ◽  
Noise Abatement ◽  
Civil Aircraft ◽  
Final Profile

A seamless and smooth morphing leading edge has remarkable potential for noise abatement and drag reduction of civil aircraft. Variable-stiffness compliant skin based on tailored composite laminate is a concept with great potential for morphing leading edge, but the currently proposed methods have difficulty in taking the manufacturing constraints or layup sequence into account during the optimization process. This paper proposes an innovative two-step design method for a variable-stiffness compliant skin of a morphing leading edge, which includes layup optimization and layup adjustment. The combination of these two steps can not only improve the deformation accuracy of the final profile of the compliant skin but also easily and effectively determine the layup sequence of the composite layup. With the design framework, an optimization model is created for a variable-stiffness compliant skin, and an adjustment method for its layups is presented. Finally, the deformed profiles between the directly optimized layups and the adjusted ones are compared to verify its morphing ability and accuracy. The final results demonstrate that the obtained deforming ability and accuracy are suitable for a large-scale aircraft wing.

scholarly journals Nano-imprinted subwavelength gratings as polarizing beamsplitters

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Julian Wüster ◽  
Yannick Bourgin ◽  
Patrick Feßer ◽  
Arne Behrens ◽  
Stefan Sinzinger
Keyword(s):  
Nanoimprint Lithography ◽  
Optical Measurement ◽  
Design Method ◽  
Optical Systems ◽  
Surface Metrology ◽  
Measurement Systems ◽  
Common Path ◽  
Dielectric Coatings ◽  
Subwavelength Gratings ◽  
Wide Range

AbstractPolarizing beamsplitters have numerous applications in optical systems, such as systems for freeform surface metrology. They are classically manufactured from birefringent materials or with stacks of dielectric coatings. We present a binary subwavelength-structured form-birefringent diffraction grating, which acts as a polarizing beamsplitter for a wide range of incidence angles −30∘…+30∘. We refine the general design method for such hybrid gratings. We furthermore demonstrate the manufacturing steps with Soft-UV-Nanoimprint-Lithography, as well as the experimental verification, that the structure reliably acts as a polarizing beamsplitter. The experimental results show a contrast in efficiency for TE- and TM-polarization of up to 1:18 in the first order, and 34:1 in the zeroth order. The grating potentially enables us to realize integrated compact optical measurement systems, such as common-path interferometers.

scholarly journals Dynamic Accuracy Design Method of Ultra-precision Machine Tool

2018 ◽  
Vol 31 (1) ◽  
Author(s):  
Guo-Da Chen ◽  
Ya-Zhou Sun ◽  
Fei-Hu Zhang ◽  
Li-Hua Lu ◽  
Wan-Qun Chen ◽  
...  
Keyword(s):  
Machine Tool ◽  
Design Method ◽  
Dynamic Accuracy ◽  
Precision Machine ◽  
Ultra Precision

scholarly journals Flowline Optical Simulation to Refractive/Reflective 3D Systems: Optical Path Length Correction

Photonics ◽  
2019 ◽  
Vol 6 (4) ◽  
pp. 101 ◽  
Author(s):  
Angel García-Botella ◽  
Lun Jiang ◽  
Roland Winston
Keyword(s):  
Vector Field ◽  
Path Length ◽  
Optical Design ◽  
Radiant Energy ◽  
Computation Time ◽  
Optical Path Length ◽  
Optical Path ◽  
Optical Systems ◽  
Optical Simulation ◽  
Reflective Systems

Nonimaging optics is focused on the study of techniques to design optical systems for the purpose of energy transfer instead of image forming. The flowline optical design method, based on the definition of the geometrical flux vector J, is one of these techniques. The main advantage of the flowline method is its capability to visualize and estimate how radiant energy is transferred by the optical systems using the concepts of vector field theory, such as field line or flux tube, which overcomes traditional raytrace methods. The main objective this paper is to extend the flowline method to analyze and design real 3D concentration and illumination systems by the development of new simulation techniques. In this paper, analyzed real 3D refractive and reflective systems using the flowline vector potential method. A new constant term of optical path length is introduced, similar and comparable to the gauge invariant, which produces a correction to enable the agreement between raytrace- and flowline-based computations. This new optical simulation methodology provides traditional raytrace results, such as irradiance maps, but opens new perspectives to obtaining higher precision with lower computation time. It can also provide new information for the vector field maps of 3D refractive/reflective systems.

scholarly journals Catadioptric Optical System Design of 15-Magnitude Star Sensor with Large Entrance Pupil Diameter

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5501
Author(s):  
Yang Bai ◽  
Jianlin Li ◽  
Rongwei Zha ◽  
Ying Wang ◽  
Guangzhi Lei
Keyword(s):  
Optical System ◽  
Attitude Control ◽  
Pupil Diameter ◽  
Focal Length ◽  
Field Of View ◽  
Star Sensor ◽  
Spherical Lens ◽  
Entrance Pupil ◽  
Secondary Mirror ◽  
Entrance Pupil Diameter

The optical system is one of the core components for star sensors, whose imaging quality directly influences the performance of star sensors for star detection, thereby determining the attitude control accuracy of spacecrafts. Here, we report a new type of optical system with a catadioptric structure and a large entrance pupil diameter for a 15-magnitude star sensor. It consists of an improved Cassegrain system (R-C system), an aperture correction spherical lens group and a field of view correction spherical lens group. By embedding the secondary mirror of the R-C system into the output surface of the negative spherical lens of the aperture correction spherical lens group, the blocking of incident light is eliminated from the secondary mirror holder. After the structure optimization, the catadioptric optical system (COS) had a spectral range of 450 nm–950 nm, an entrance pupil diameter of 250 mm, a half-diagonal field of view of 1.4° and a focal length of 390 mm. By using theoretical calculations and experimental measurements, it was verified that the COS, with the ability to correct astigmatism, lateral color and distortion, can fulfill the detection of 15-magnitude dark stars.

scholarly journals A Part Consolidation Design Method for Additive Manufacturing based on Product Disassembly Complexity

2020 ◽  
Vol 10 (3) ◽  
pp. 1100 ◽  
Author(s):  
Samyeon Kim ◽  
Seung Ki Moon
Keyword(s):  
Additive Manufacturing ◽  
End Of Life ◽  
Design Method ◽  
Life Stage ◽  
Product Recovery ◽  
Manufacturing Constraints ◽  
Part Consolidation ◽  
Product Disassembly ◽  
Part Complexity ◽  
Manufacturing Stage

Parts with complex geometry have been divided into multiple parts due to manufacturing constraints of conventional manufacturing. However, since additive manufacturing (AM) is able to fabricate 3D objects in a layer-by-layer manner, design for AM has been researched to explore AM design benefits and alleviate manufacturing constraints of AM. To explore more AM design benefits, part consolidation has been researched for consolidating multiple parts into fewer number of parts at the manufacturing stage of product lifecycle. However, these studies have been less considered product recovery and maintenance at end-of-life stage. Consolidated parts for the manufacturing stage would not be beneficial at end-of-life stage and lead to unnecessary waste of materials during maintenance. Therefore, in this research, a design method is proposed to consolidate parts for considering maintenance and product recovery at the end-of-life stage by extending a modular identification method. Single part complexity index (SCCI) is introduced to measure part and interface complexities simultaneously. Parts with high SCCI values are grouped into modules that are candidates for part consolidation. Then the product disassembly complexity (PDC) can be used to measure disassembly complexity of a product before and after part consolidation. A case study is performed to demonstrate the usefulness of the proposed design method. The proposed method contributes to guiding how to consolidate parts for enhancing product recovery.

Behavior Characteristics of Nano-Stage According to Hinge Structure

2007 ◽  
Vol 7 (11) ◽  
pp. 4146-4149 ◽  
Author(s):  
Hyun-Seong Oh ◽  
Sung-Jun Lee ◽  
Yong-Woo Kim ◽  
Deug-Woo Lee
Keyword(s):  
Optical Systems ◽  
Precision Machining ◽  
System Control ◽  
Nano Scale ◽  
Composite Joint ◽  
Ultra Precision ◽  
Probe Microscope ◽  
Motion Stage ◽  
Scale Motion ◽  
Behavior Characteristics

Nano-stages are used in many ultra-precision systems, such as scanning probe microscope (SPM), optical fiber aligners, ultra-precision cutting, measuring and optical systems. Generally, ultra-precision machining and measuring are achieved using a nano-scale motion stage actuated using Piezo-electric actuators (PZT), and the importance of and demands for the motion stage increase with the need to improve system performance and accuracy. However, it is difficult to find solutions because the performance and characteristics of nano-scale motion stages are determined by various factors, such as the hinge structure, actuator, and method of system control. This paper focuses on improving of leafspring and planar joint hinges, and suggests a composite joint hinge stage.

The Experiment Investigation of the Tool Wear in Diamond Ultra-Precision Cutting of Aluminum Alloy Mirror

2015 ◽  
Vol 667 ◽  
pp. 162-167
Author(s):  
Guo Jun Dong ◽  
Yuan Jing Zhang ◽  
Ming Zhou
Keyword(s):  
Aluminum Alloy ◽  
Tool Wear ◽  
Mass Density ◽  
Low Cost ◽  
Cutting Speed ◽  
High Strength ◽  
Optical Systems ◽  
Infrared Band ◽  
Tool Wear Mechanism ◽  
Ultra Precision

Due to its relatively low mass density, low cost, high strength, the aluminum alloy is an ideal optical material to fabricate the large metal mirror of infrared band optical systems. The diamond ultra-precision cutting can produce ultra smooth machined surfaces without other finishing processes. Consequently, it can be used as a effective method to fabricate the large metal mirror. However, the tool wear is severe during the ultra-precision processes, which will ruduces the surface error of the large metal mirror. In this work, the ultra-precision cutting tests were performed to investigate the tool wear. The tool wear was examined by using a scanning electron microscope (SEM), and the chip was examined by using x-ray energy dispersive spectrdmeter (EDS). The tool wear mechanism and the influence of the chutting parameters on the tool wear were investigated. The results show that the daimond tool occurred abrasive wear and diffusing wear in the diamond ultra-precision cutting of aluminum alloy. The average clearance wear width increases with an increase of the cutting speed and the feed rate. There is a slight rise in the average clearance wear width as the depth of the cut increases in the range of 5μm-15μm. The average clearance wear width obviously increases when the depth of the cut reaches to 20μm.

Optical Design of Very Large Four-Mirror Systems

2007 ◽  
Vol 364-366 ◽  
pp. 1231-1236 ◽  
Author(s):  
Li Rong Zhu ◽  
Wei Min Shen
Keyword(s):  
Focal Length ◽  
Optical Design ◽  
Diffraction Limit ◽  
Field Of View ◽  
Initial Structure ◽  
Entrance Pupil ◽  
Primary Mirror ◽  
Imaging Quality ◽  
Large Aperture ◽  
Design Idea

Four-mirror systems with a very large aperture and a long focal length were investigated and designed. Their design idea is given. Through the derivation of primary aberration formula, the aberration properties were analyzed and discussed, and the method to determine its initial structure is reported. As examples, two four-mirror systems with spherical and parabolic primary mirror, 100m focal length, and 10m entrance pupil were optimally designed. Their imaging quality approaches diffraction limit within field of view of 0.4 and 0.5 degrees respectively.

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