Precision Optics Manufacturing最新文献_第5页

Cutting high-performance materials with ultrasonically modulated cutting speed 用超声波调制切割速度切割高性能材料

Precision Optics Manufacturing Pub Date : 2020-07-08 DOI: 10.1117/12.2565757

Armin Reif, Sebastian Sitzberger, R. Rascher

{"title":"Cutting high-performance materials with ultrasonically modulated cutting speed","authors":"Armin Reif, Sebastian Sitzberger, R. Rascher","doi":"10.1117/12.2565757","DOIUrl":"https://doi.org/10.1117/12.2565757","url":null,"abstract":"The continuing trend towards lightweight construction and the associated machining rates of up to 95 % lead to an increased use of high-performance materials. The ever growing demands on the strength and quality of components and the associated use of materials which are hard to machine require the further development of new, economical machining techniques. In ultrasonic-assisted machining, an additional high-frequency vibration is superimposed on the conventional machining process. The vibration of the tool is usually excited axially or longitudinally to the workpiece, i.e. vertical to the cutting direction. An additional vibration overlay around the rotation axis (torsional) of the tool is also possible. This generates a vibration overlay in the cutting direction. The vibration initiation causes vibration amplitudes in the range of a few micrometers at the tool cutting edge. This leads in turn to a high-frequency change in the cutting speed or feed rate. Overall, an additional torsional vibration overlap can further reduce cutting forces, increase tool life and improve workpiece quality. In order for a grinding tool to generate a torsional vibration, a special tool was required that had to be designed by simulation. The formation of a torsional vibration was achieved by helical slots in the sonotrode. Depending on the angle of rotation and the length of the slots, a part of the axial vibration is converted into a torsional vibration by an axial excitation of the sonotrode. The aim in designing the slots was to achieve the highest possible vibration amplitude. Following the simulation, the slots were inserted into the tool in the corresponding optimum geometric position. Afterwards, the specially designed grinding tool was validated by machining the brittle-hard glass-ceramic material Zerodur. The first test results with the torsionally vibrating tool are presented in the following.","PeriodicalId":422212,"journal":{"name":"Precision Optics Manufacturing","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122349305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Manufacturing of optical elements by non-contact laser processing 非接触式激光加工制造光学元件

Precision Optics Manufacturing Pub Date : 2020-07-08 DOI: 10.1117/12.2564713

S. Schwarz, S. Rung, C. Esen, R. Hellmann

{"title":"Manufacturing of optical elements by non-contact laser processing","authors":"S. Schwarz, S. Rung, C. Esen, R. Hellmann","doi":"10.1117/12.2564713","DOIUrl":"https://doi.org/10.1117/12.2564713","url":null,"abstract":"We report on a photonic process chain to manufacture optical elements by non-contact all laser based micro-processing. Firstly, pre-defined optics geometries are generated by high-precision 1030 nm femtosecond layer-by-layer ablation. In order to meet high surface quality requirements, inevitable stipulated for optical use, the surface of thus generated elements has to be smoothened by subsequent 10.6 μm CO2 laser polishing. To demonstrate this surface finishing process, a complex optic geometry i.e. an axicon array consisting of 37 individual axicons is fabricated within 23 minutes while the polishing shows a reduction of the surface roughness from 0.36 μm to 48 nm. The functionality of the fabricated optic is tested using the 1030 nm wavelength ultrashort pulsed laser. Several sub-Bessel beams exhibiting the typical zeroth-order Bessel beam intensity distribution are observed, in turn confirming the applied manufacturing process to be well applicable for the fabrication of complex optic geometries. Cross sections of the quasi-Bessel beam at the axicon in the middle of the array in both, x- and y-direction, show an almost identical intensity profile, indicating the high contour accuracy of the axicon. Detailed investigations of the axicon in the middle of the array show a tip rounding of 1.37 mm while the sub-beam behind this axicon is measured to have a diameter of 9.5 μm (FWHM) and a Bessel range in propagation direction of 8.0 mm (FWHM).","PeriodicalId":422212,"journal":{"name":"Precision Optics Manufacturing","volume":"395 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133910865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulating the actual imaging in the individual eye: a novel approach to calculating spectacle lenses 模拟个体眼睛的实际成像:计算眼镜镜片的新方法

Precision Optics Manufacturing Pub Date : 2020-07-08 DOI: 10.1117/12.2564665

S. Trumm, W. Becken, Yohann Bénard, G. Esser, D. Uttenweiler

引用次数: 0

Setup of a new form measurement system for flat and slightly curved optics with diameters up to 1.5 metres 为直径达1.5米的平面和微弯曲光学元件建立一种新型测量系统

Precision Optics Manufacturing Pub Date : 2020-07-08 DOI: 10.1117/12.2564912

G. Ehret, Jan Spichtinger, M. Stavridis, M. Schulz

引用次数: 2

Force and pressure analysis during overarm polishing 臂上抛光过程中的力和压力分析

Precision Optics Manufacturing Pub Date : 2020-07-08 DOI: 10.1117/12.2564903

Michael F. Benisch, O. Fähnle, R. Rascher, W. Bogner

引用次数: 2

High precision glass polishing with ketchup 高精度玻璃抛光与番茄酱

Precision Optics Manufacturing Pub Date : 2020-07-08 DOI: 10.1117/12.2564867

M. Schneckenburger, Melanie Schiffner, R. Börret

{"title":"High precision glass polishing with ketchup","authors":"M. Schneckenburger, Melanie Schiffner, R. Börret","doi":"10.1117/12.2564867","DOIUrl":"https://doi.org/10.1117/12.2564867","url":null,"abstract":"Due to the advantages over conventional polishing strategies, polishing with non-Newtonian fluids are state of the art in precision shape correction of precision optical glass surfaces. The viscosity of such fluids is not constant since it changes as a function of shear rate and time. An example is during the shape correction by polishing with pitch or ice, where pitch flows slowly under its own weight and acts like a solid body during short periods of stress as its viscosity increases. One approach is to use thixotropic fluids like ketchup to reduce the roughness by polishing, without changing the shape of the sample. Tomato ketchup shows a time-dependent change in viscosity: the longer the ketchup undergoes shear stress, the lower is its viscosity. Therefore, in this article, a new processing is put forward to polishing glass surfaces with ketchup containing micro-sized Ce2O. Besides conventional ketchup, curry ketchup and an organic product were tested as well. An industrial robot onto the work piece surface guides the polishing head. The different types of ketchup are compared by means of roughness and shape accuracy and the potential regarding to manufacture high-precise optical glass surfaces.","PeriodicalId":422212,"journal":{"name":"Precision Optics Manufacturing","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124414164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Machine learning model for robot polishing cell 机器人抛光电池的机器学习模型

Precision Optics Manufacturing Pub Date : 2020-07-08 DOI: 10.1117/12.2564633

M. Schneckenburger, L. Garcia-Barth, R. Börret

{"title":"Machine learning model for robot polishing cell","authors":"M. Schneckenburger, L. Garcia-Barth, R. Börret","doi":"10.1117/12.2564633","DOIUrl":"https://doi.org/10.1117/12.2564633","url":null,"abstract":"The quality of optical components such as lenses or mirrors can be described by shape errors and surface roughness. With increasing optic sizes, the stability of the polishing process becomes more and more important. If not empirically known, the optical surface must be measured after each polishing step. One approach is to mount sensors on the polishing head in order to measure process relevant quantities. On the basis of these data, Machine Learning algorithms can be applied for surface value prediction. The aim of this work is the stepwise development of an artificial neural network (ANN) in order to improve the accuracy of the models' prediction. The ANN is developed in the Python programming language using the Keras deep learning library. Beginning with simple network architecture and common training parameters. The model will then be optimized step-by-step through the implementation of different methods and Hyperparameter optimization (HPO). Data, which is generated by the sensor-integrated glass polishing head, is used to train the ANN-model. A representative part of these data is held back before, in order to validate the models' prediction. The so-called dataset contains measured values from multiple polishing runs, preceded by a design of experiment. After the model is trained on the dataset, it is able to predict the result of not yet performed polishing runs, with given polishing parameters. Concrete, the ANN is used to predict the resulting glass-surface quality, which includes the surface roughness and the shape accuracy, calculated by the material removal over time. The prediction by artificial neural networks reduces the polishing iterations and thus the production time.","PeriodicalId":422212,"journal":{"name":"Precision Optics Manufacturing","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123683775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

On the metrology and analysis of MSF error MSF误差的计量与分析

Precision Optics Manufacturing Pub Date : 2020-07-08 DOI: 10.1117/12.2566251

Olga Kukso, R. Rascher, M. Pohl, R. Boerret

引用次数: 0

Micro lens arrays made by CO2-laser radiation 由二氧化碳激光辐射制成的微透镜阵列

Precision Optics Manufacturing Pub Date : 2020-07-08 DOI: 10.1117/12.2566485

T. Schmidt, D. Conrad

引用次数: 2

Optical freeform generation of N-BK7 by fluorine‐based plasma jet machining 氟基等离子体射流加工N-BK7的光学自由曲面

Precision Optics Manufacturing Pub Date : 2020-07-08 DOI: 10.1117/12.2564913

Faezeh Kazemi, G. Boehm, T. Arnold

引用次数: 1