In recent years, much progress has been made on the development of metal mirrors based on additive manufacturing (AM). The sandwich mirror is well known for its excellent mechanical properties and challenging machining. Now, AM can be used to fabricate this complex structure and reduce the processing time and cost. In addition, with the aid of some new design methods for additive manufacturing, such as lattice, topology optimization (TO), and Voronoi, the freedom of mirror structure design is enormously improved. The common materials of mirrors include ceramics (SiC), glasses (glass ceramics, fused silica), and metals (aluminum, beryllium). Among them, the AM technology of metals is the most mature and widely used. Researchers have recently extensively developed the new-generation metal mirror to improve performance and lightweight rate. This review focuses on the following topics: (1) AM technologies and powder materials for metal mirrors, (2) recent advances in optomechanical design methods for AM metal mirrors, (3) challenges faced by AM metal mirrors in fabricating, and (4) future trends in AM metal mirrors.

Design and Fabrication Technology of Metal Mirrors Based on Additive Manufacturing: A Review

The NiP coating has excellent wear and corrosion resistance, and electroless nickel-phosphorus coating is one of the best measures for surface modification of metal optical devices. The NiP layer could be processed by single-point diamond turning (SPDT). However, the periodic marks on the surface of the NiP coating processed by SPDT will lead to diffraction and stray light, which will reduce the reflectivity and image quality of the mirror. This paper studied smoothing polishing based on chemical mechanical polishing to remove turning periodic marks efficiently. Firstly, we studied the chemical corrosion and mechanical removal mechanism of smoothing polishing of the NiP coating through theoretical analysis. Then, the influencing factors of processing the quality of smoothing polishing are analyzed, and the optimal machining parameters and polishing slurry formula are formulated. Finally, through the developed process, the surface roughness of Root Mean Square (RMS) 0.223 nm is realized on the NiP coating, and an ultra-smooth surface that can meet the service accuracy of a hard X-ray mirror is obtained. Our research simplifies the high-precision machining process of the NiP coating and improves the machining efficiency. Therefore, it can be used as a new high-precision manufacturing NiP coating method.

/pdf/a-high-efficiency-and-precision-smoothing-polishing-method-1qypcvlj.pdf

A High Efficiency and Precision Smoothing Polishing Method for NiP Coating of Metal Mirror

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.

Design and Optimization for Mounting Primary Mirror with Reduced Sensitivity to Temperature Change in an Aerial Optoelectronic Sensor

Aluminum (Al) alloy is a kind of soft-plastic metal, and traditional chemical mechanical polishing (CMP) is easy to produce scratches on the polished surface and embed of abrasives, resulting in the degradation of devices. In addition, conventional CMP generally employs toxic and corrosive slurries, leading to the pollution of environment. To address these challenges, a novel green CMP was developed for Al alloy, consisting of ceria, silica, sodium carbonate, hydrogen peroxide, glycine and deionized water. After CMP, surface roughness Sa is 0.258 nm under an area of 100 × 100 μm2, which is the lowest surface roughness reported previously in such a big measurement area for Al alloy. Transmission electron microscopy confirms that the thickness of damaged layer is merely 4.6 nm. X-ray photoelectron microscopy and Fourier transform infrared spectroscopy reveal that composite abrasives are conducive for the generation of Al-O, Al-O-Si and Ce-Al bonds on the polished surface. Molecular dynamics simulations elucidate that the subsurface damage is mainly caused by exerted loading of abrasives on amorphous layer, as well as vacancy induced through the annihilation of dislocations profoundly. These outcomes provide a new avenue to manufacture atomic surfaces of soft-plastic metals for latent applications in devices. 

Novel green chemical mechanical polishing for an aluminum alloy and mechanisms interpreted by molecular dynamics simulations and measurements

FreeformNet: Fast and automatic generation of multiple-solution freeform imaging systems enabled by deep-learning

The invention relates to a large-caliber solar telescope full absorption thermal diaphragm based on dual-channel cooling. The large-caliber solar telescope full absorption thermal diaphragm has smallinterference to light path, is easy to control in temperature, and is less likely to be affected by environment, so that the solar telescope delivers a much better observation effect. Structurally, the thermal diaphragm comprises a shell, an absorption screen, a middle cone, and a conic view field diaphragm that are arranged coaxially in sequence from outside to inside, wherein an outer pressure cavity is formed between the shell and the absorption screen, an absorption cavity is formed between the absorption screen and the middle cone, an internal pressure cavity is formed between the middlecone and the conic view field diaphragm, an entrance water storage tank communicated with the internal pressure cavity is arranged outside the internal pressure cavity, the entrance water storage tankis provided with a liquid inlet tube, the water inlet tube is communicated with a cooling liquid supply device, an external pressure cavity and the internal pressure cavity are communicated through aconnection tube, one end of a liquid outlet tube is communicated with the external pressure cavity, the other end thereof is communicated with the cooling liquid supply device.

Large-aperture solar telescope full-absorption thermal diaphragm based on dual-channel cooling

The utility model relates to a three-waveband airborne laser radar system The system realizes high-efficiency, high-precision, high-resolution, large-range and long-distance detection work of each area of the coastal zone The main principle is that a laser light source synchronously emits three beams of laser pulses with different wavelengths and sends an initial trigger signal to a timing system, and the timing system starts timing; the three beams of laser pulses enter the scanning system after being expanded and collimated by the transmitting system; the scanning system controls the laserpulse to scan the surface of the to-be-measured target, the laser pulse is reflected by the surface of the to-be-measured target and then returns to the scanning system, and the scanning system reflects the echo optical signal to the receiving optical path system; the receiving optical path system collects echo optical signals and reflects the echo optical signals to the laser detection system; the laser detection system converts the received echo optical signal into a photocurrent signal and outputs the photocurrent signal; and the timing system ends timing after receiving the photocurrent signal so as to obtain distance information from the surface of the to-be-measured target to the scanning system

Three-waveband airborne laser radar system

The invention provides a total reflection type underwater camera suitable for a deep sea environment. The camera comprises window glass, a detector shell, a detector and a reflective optical system, wherein a light through hole is formed in one end of the detector shell, the other end of the detector shell is closed, and the window glass and the detector are sequentially arranged in the detector shell in the light incident direction; the reflective optical system is positioned in front of the light through hole and is fixedly mounted on the detector shell; the reflective optical system is provided with a light inlet and at least one reflector, and the relative positions of the light inlet and at least one reflector must ensure that light beams passing through the light inlet can pass through the light through hole and the window glass in sequence after being reflected by at least one reflector and are finally received by the detector. The camera avoids the influence of high-intensity pressure difference caused by an air-water interface on the reflective optical system and can be used in the deep sea environment.

Total reflection type underwater camera suitable for deep sea environment

Freeform optics offers more degrees of freedom to optical design that can benefit from a compact package size and a large field of view for imaging systems. Motivated by the advances in modern optical fabrication and metrology, freeform optics has been found in many applications. In this paper, we will describe the challenging optical design, fabrication, metrology, and assembly of an all-aluminum unobscured two-mirror freeform imaging telescope. The telescope has a large field of view of 20∘×15∘. The freeform aluminum mirrors are manufactured by diamond turning based on a feedback modification strategy. The freeform mirrors are measured by a computer-generated hologram-based interferometric null test method. All-aluminum configuration has the advantages of being athermal and cost-effective.

Optical design and fabrication of an all-aluminum unobscured two-mirror freeform imaging telescope.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Xu Zhichen

Author Tools

Chat about Author

Papers

Large-aperture solar telescope full-absorption thermal diaphragm based on dual-channel cooling

Three-waveband airborne laser radar system

Total reflection type underwater camera suitable for deep sea environment

Optical design and fabrication of an all-aluminum unobscured two-mirror freeform imaging telescope.