Optical Angular Momentum最新文献_第5页

Use of schlieren methods to study gas flow in laser technology 用纹影法研究激光技术中的气体流动

Optical Angular Momentum Pub Date : 2016-11-11 DOI: 10.1117/12.2257212

L. Mrňa, J. Pavelka, P. Horník, J. Hrabovsky

{"title":"Use of schlieren methods to study gas flow in laser technology","authors":"L. Mrňa, J. Pavelka, P. Horník, J. Hrabovsky","doi":"10.1117/12.2257212","DOIUrl":"https://doi.org/10.1117/12.2257212","url":null,"abstract":"Laser technologies such as welding and cutting rely on process gases. We suggest to use schlieren imaging to visualize the gas flow during these processes. During the process of laser welding, the shielding gas flows to the welded area to prevent oxidation of the weld pool by surrounding air. The gas also interacts with hot plasma spurting from the key hole induced by the laser beam incident on the molten material. This interaction is quite complicated because hot plasma mixes with the cold shielding gas while the system is moving along the weld. Three shielding gases were used in the presented experiment: Ar, He and N2. Differences in dynamics of the flow are clearly visible on schlieren images. Moreover, high speed recording reveals a structure consisting of hot gas bubbles. We were also able to determine the velocity of the bubbles from the recording. During laser cutting, the process gas flows coaxially with the laser beam from the nozzle to remove the molten material out of the kerf. The gas flow is critical for the quality of the resulting edge of the cut. Schlieren method was used to study gas flow under the nozzle and then under the material being cut. This actually creates another slot nozzle. Due to the very low speed of flow below the material the schleiren method is already at the limit of its sensitivity. Therefore, it is necessary to apply a differential technique to increase the contrast. Distinctive widening of the flow shaped by the kerf was observed.","PeriodicalId":112965,"journal":{"name":"Optical Angular Momentum","volume":"226 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130586463","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

Detection and magnification of bridge displacements using video images 利用视频图像检测和放大桥梁位移

Optical Angular Momentum Pub Date : 2016-11-11 DOI: 10.1117/12.2257218

Leticia Teran, C. Ordóñez, S. Garcia-Cortes, Agustín Menéndez

引用次数: 4

Control of chemical composition of PZT thin films produced by ion-beam deposition from a multicomponent target 多组分靶离子束沉积PZT薄膜化学成分的控制

Optical Angular Momentum Pub Date : 2016-11-11 DOI: 10.1117/12.2257331

J. Hlubuček, David Vápenka, P. Horodyska, J. Václavík

{"title":"Control of chemical composition of PZT thin films produced by ion-beam deposition from a multicomponent target","authors":"J. Hlubuček, David Vápenka, P. Horodyska, J. Václavík","doi":"10.1117/12.2257331","DOIUrl":"https://doi.org/10.1117/12.2257331","url":null,"abstract":"Lead zirconate titanate (PZT) is widely used for its ferroelectric and piezoelectric properties, which are conditioned by perovskite structure. Crystallization into this desired phase is determined also by a proper stoichiometry, where the lead concentration is a crucial parameter. The crystallization process takes place during annealing under high temperatures, which is linked to heavy lead losses, so the lead has to be in excess. Therefore, this paper is devoted to the control of chemical composition of PZT thin films deposited via ion beam sputtering (IBS). A commonly used approach for IBS relies on employing a multicomponent target to obtain films with the same composition as that of the target. However, in the case of PZT it is favorable to have the ability to controllably change the chemical composition of thin films in order to acquire high perovskite content. Our study revealed that the determinative lead content in PZT layers prepared by simple and dual ion-beam deposition from a multicomponent target can be easily controlled by the power of primary ion source. At the same time, the composition is also dependent on the substrate temperature and the power of assistant ion source. Thin PZT films with more than 30 % lead excess were acquired from a stoichiometric multicomponent target (i.e. a target without any lead excess). We can therefore propose several possible sets of deposition parameters suitable for the PZT deposition via IBS to obtain high perovskite content.","PeriodicalId":112965,"journal":{"name":"Optical Angular Momentum","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133028205","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

Zeeko precession for free-form polishing Zeeko进动自由形式抛光

Optical Angular Momentum Pub Date : 2016-11-11 DOI: 10.1117/12.2256558

F. Procháska, I. Poláková, J. Polák, O. Matousek, D. Tomka

引用次数: 2

Geometric calibration of rotational kaleidoscopic instrument 旋转万花筒仪器的几何定标

Optical Angular Momentum Pub Date : 2016-11-11 DOI: 10.1117/12.2257434

V. Havran, S. Nemcová, J. Cáp, J. Hošek, Jiří Bittner, K. Macúchová

引用次数: 1

Qualification of a 3D structured light sensor for a reverse engineering application 一种用于逆向工程应用的三维结构光传感器的鉴定

Optical Angular Momentum Pub Date : 2016-11-11 DOI: 10.1117/12.2257601

Alexandre Zuquete Guarato, Alexandre C. Loja, L. P. Pereira, S. Braga, T. Trevilato

引用次数: 5

Scratch and dig analysis for Metis mirrors surfaces defects evaluation Metis反射镜表面缺陷评价的划痕和挖掘分析

Optical Angular Momentum Pub Date : 2016-11-11 DOI: 10.1117/12.2256634

M. Špína, F. Procháska, R. Melich

引用次数: 0

Methods for refractive-index homogeneity calculation using Fourier-transform phase-shifting interferometry 傅立叶变换移相干涉法计算折射率均匀性的方法

Optical Angular Momentum Pub Date : 2016-11-11 DOI: 10.1117/12.2256991

O. Matousek, V. Ledl, P. Psota, P. Vojtíšek

引用次数: 1

Visualization and measurement of the air film close ultra-hydrophobic surfaces 超疏水表面气膜的可视化和测量

Optical Angular Momentum Pub Date : 2016-11-11 DOI: 10.1117/12.2260997

D. Jašíková, M. Gašić, M. Kotek, V. Kopecký

引用次数: 0

Sol-gel preparation of silica and titania thin films 溶胶-凝胶法制备二氧化硅和二氧化钛薄膜

Optical Angular Momentum Pub Date : 2016-11-11 DOI: 10.1117/12.2257325

T. Thoř, J. Václavík

{"title":"Sol-gel preparation of silica and titania thin films","authors":"T. Thoř, J. Václavík","doi":"10.1117/12.2257325","DOIUrl":"https://doi.org/10.1117/12.2257325","url":null,"abstract":"Thin films of silicon dioxide (SiO2) and titanium dioxide (TiO2) for application in precision optics prepared via the solgel route are being investigated in this paper. The sol-gel process presents a low cost approach, which is capable of tailoring thin films of various materials in optical grade quality. Both SiO2 and TiO2 are materials well known for their application in the field of anti-reflective and also highly reflective optical coatings. For precision optics purposes, thickness control and high quality of such coatings are of utmost importance. In this work, thin films were deposited on microscope glass slides substrates using the dip-coating technique from a solution based on alkoxide precursors of tetraethyl orthosilicate (TEOS) and titanium isopropoxide (TIP) for SiO2 and TiO2, respectively. As-deposited films were studied using spectroscopic ellipsometry to determine their thickness and refractive index. Using a semi-empirical equation, a relationship between the coating speed and the heat-treated film thickness was described for both SiO2 and TiO2 thin films. This allows us to control the final heat-treated thin film thickness by simply adjusting the coating speed. Furthermore, films’ surface was studied using the white-light interferometry. As-prepared films exhibited low surface roughness with the area roughness parameter Sq being on average of 0.799 nm and 0.33 nm for SiO2 and TiO2, respectively.","PeriodicalId":112965,"journal":{"name":"Optical Angular Momentum","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114275310","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