The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Alexander V. Tikhonravov - One of the best experts on this subject based on the ideXlab platform.
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Stable Method for Optical Monitoring the Deposition of Multilayer Optical Coatings
Computational Mathematics and Mathematical Physics, 2020Co-Authors: I V Kochikov, Alexander V. Tikhonravov, Yu. S. Lagutin, A. A. Lagutina, Dmitry Lukyanenko, Anatoly G. YagolaAbstract:For Optical monitoring of layer thickness in the deposition of multilayer Optical Coatings, a stable method is proposed that completely eliminates the cumulative effect of errors in the thicknesses of deposited layers. The considered monitoring method relies on a nonlocal algorithm for analyzing data measured in the course of coating deposition monitoring. Computer simulation of coating deposition is used to demonstrate the effectiveness of the proposed type of monitoring as compared with other Optical monitoring methods.
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an error self compensation mechanism for deposition of Optical Coatings with broadband Optical monitoring
Moscow University Physics Bulletin, 2017Co-Authors: Alexander V. Tikhonravov, I V Kochikov, S A Sharapova, Valery G Zhupanov, Michael K Trubetskov, Anatoly G. YagolaAbstract:An error self-compensation mechanism is investigated for use during the deposition of Optical Coatings with broadband Optical monitoring. The correlation of thickness errors caused by monitoring procedure is mathematically described. It is shown that this correlation of errors may result in the effect of selfcompensation of errors.
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quality control of oblique incidence Optical Coatings based on normal incidence measurement data
Optics Express, 2013Co-Authors: Tatiana V. Amotchkina, Michael K Trubetskov, Alexander V. Tikhonravov, Detlev Ristau, Henrik Ehlers, Sebastian Schlichting, David L Death, Robert J Francis, Vladimir PervakAbstract:We demonstrate selection of reliable approaches for post-production characterization of oblique incidence multilayer Optical Coatings. The approaches include choice of input information, selection of adequate coating model, corresponding numerical characterization algorithm, and verification of the results. Applications of the approaches are illustrated with post-production characterization of oblique incidence edge filter, oblique incidence beam splitter and oblique incidence 43-layer quarter-wave mirror.
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Design and monitoring approaches for the production of high quality Optical Coatings
Seventh International Conference on Thin Film Physics and Applications, 2010Co-Authors: Alexander V. Tikhonravov, Michael K TrubetskovAbstract:ABSTRACT Modern design and monitoring approaches are discussed from the point of view of their ability to provide a production of high quality Optical Coatings at the lowest possible cost and in the most reasonable time frame. Keywords: Interference Coatings, design, monitoring, computational manufacturing 1. INTRODUCTION The invention of the needle optimization technique 1 and further modifications of this technique 2, 3 provided Optical coating engineers with the most effective tools for designing of Optical Coatings of any type. An outstanding computational efficiency of modern design techniques has resulted in a new paradigm of designing of Optical Coatings. 4 This new paradigm proposes to look for a practically optimal design instead of a formally optimal design characterized by the lowest possible merit function value. The concept of a practically optimal design is tightly connected with a monitoring approach used for Optical coating production. At the modern state of art in production of innovative Optical Coatings, especially in production of high quality Optical coa tings for challenging applications, it is necessary to perform a combined choice of design and monitoring approach that should be applied for Optical coating manufacturing. Modern design techniques can provide a great number of excellent theoretical designs and it is too expensive and time consuming to perform test manufacturing runs in order to choose the most practical design with the best expectation for a high manufacturing yield. An excellent alternative to real test manu facturing runs is provided by a series of experiments with computational manufacturing of Optical Coatings.
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Achievements and Challenges in the Design and Production of High Quality Optical Coatings
IEICE Transactions on Electronics, 2008Co-Authors: Alexander V. Tikhonravov, Michael K Trubetskov, Ichiro KasaharaAbstract:A new paradigm in the design of Optical Coatings connected with an outstanding computational efficiency of modern design techniques is discussed. Several other topics including pre-production error analysis, monitoring of coating production, and computational manufacturing of Optical Coatings are considered.
Michael K Trubetskov - One of the best experts on this subject based on the ideXlab platform.
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an error self compensation mechanism for deposition of Optical Coatings with broadband Optical monitoring
Moscow University Physics Bulletin, 2017Co-Authors: Alexander V. Tikhonravov, I V Kochikov, S A Sharapova, Valery G Zhupanov, Michael K Trubetskov, Anatoly G. YagolaAbstract:An error self-compensation mechanism is investigated for use during the deposition of Optical Coatings with broadband Optical monitoring. The correlation of thickness errors caused by monitoring procedure is mathematically described. It is shown that this correlation of errors may result in the effect of selfcompensation of errors.
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quality control of oblique incidence Optical Coatings based on normal incidence measurement data
Optics Express, 2013Co-Authors: Tatiana V. Amotchkina, Michael K Trubetskov, Alexander V. Tikhonravov, Detlev Ristau, Henrik Ehlers, Sebastian Schlichting, David L Death, Robert J Francis, Vladimir PervakAbstract:We demonstrate selection of reliable approaches for post-production characterization of oblique incidence multilayer Optical Coatings. The approaches include choice of input information, selection of adequate coating model, corresponding numerical characterization algorithm, and verification of the results. Applications of the approaches are illustrated with post-production characterization of oblique incidence edge filter, oblique incidence beam splitter and oblique incidence 43-layer quarter-wave mirror.
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Design and monitoring approaches for the production of high quality Optical Coatings
Seventh International Conference on Thin Film Physics and Applications, 2010Co-Authors: Alexander V. Tikhonravov, Michael K TrubetskovAbstract:ABSTRACT Modern design and monitoring approaches are discussed from the point of view of their ability to provide a production of high quality Optical Coatings at the lowest possible cost and in the most reasonable time frame. Keywords: Interference Coatings, design, monitoring, computational manufacturing 1. INTRODUCTION The invention of the needle optimization technique 1 and further modifications of this technique 2, 3 provided Optical coating engineers with the most effective tools for designing of Optical Coatings of any type. An outstanding computational efficiency of modern design techniques has resulted in a new paradigm of designing of Optical Coatings. 4 This new paradigm proposes to look for a practically optimal design instead of a formally optimal design characterized by the lowest possible merit function value. The concept of a practically optimal design is tightly connected with a monitoring approach used for Optical coating production. At the modern state of art in production of innovative Optical Coatings, especially in production of high quality Optical coa tings for challenging applications, it is necessary to perform a combined choice of design and monitoring approach that should be applied for Optical coating manufacturing. Modern design techniques can provide a great number of excellent theoretical designs and it is too expensive and time consuming to perform test manufacturing runs in order to choose the most practical design with the best expectation for a high manufacturing yield. An excellent alternative to real test manu facturing runs is provided by a series of experiments with computational manufacturing of Optical Coatings.
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Achievements and Challenges in the Design and Production of High Quality Optical Coatings
IEICE Transactions on Electronics, 2008Co-Authors: Alexander V. Tikhonravov, Michael K Trubetskov, Ichiro KasaharaAbstract:A new paradigm in the design of Optical Coatings connected with an outstanding computational efficiency of modern design techniques is discussed. Several other topics including pre-production error analysis, monitoring of coating production, and computational manufacturing of Optical Coatings are considered.
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Online characterization and reoptimization of Optical Coatings
Advances in Optical Thin Films, 2004Co-Authors: Alexander V. Tikhonravov, Michael K TrubetskovAbstract:We present algorithms that can be used for the on-line characterization and reoptimization of Optical Coatings in various production environments, even in situations when coating layers are not bulk-like and their parameters may change after the exposition to air. The questions of accuracy and practical implementation of these algorithms are discussed.
G M Harry - One of the best experts on this subject based on the ideXlab platform.
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thermal noise from Optical Coatings in gravitational wave detectors
Applied Optics, 2006Co-Authors: G M Harry, H Armandula, Eric D Black, D R M Crooks, G Cagnoli, J Hough, P G Murray, S Reid, S Rowan, P SneddonAbstract:Gravitational waves are a prediction of Einstein's general theory of relativity. These waves are created by massive objects, like neutron stars or black holes, oscillating at speeds appreciable to the speed of light. The detectable effect on the Earth of these waves is extremely small, however, creating strains of the order of 10−21. There are a number of basic physics experiments around the world designed to detect these waves by using interferometers with very long arms, up to 4 km in length. The next-generation interferometers are currently being designed, and the thermal noise in the mirrors will set the sensitivity over much of the usable bandwidth. Thermal noise arising from mechanical loss in the Optical Coatings put on the mirrors will be a significant source of noise. Achieving higher sensitivity through lower mechanical loss Coatings, while preserving the crucial Optical and thermal properties, is an area of active research right now.
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thermal noise in interferometric gravitational wave detectors due to dielectric Optical Coatings
Classical and Quantum Gravity, 2002Co-Authors: G M Harry, S Rowan, Andri M Gretarsson, P R Saulson, Scott E Kittelberger, Steven D Penn, William J Startin, Martin M Fejer, D R M CrooksAbstract:We report on thermal noise from the internal friction of dielectric Coatings made from alternating layers of Ta2O5 and SiO2 deposited on fused silica substrates. We present calculations of the thermal noise in gravitational wave interferometers due to Optical Coatings, when the material properties of the coating are different from those of the substrate and the mechanical loss angle in the coating is anisotropic. The loss angle in the Coatings for strains parallel to the substrate surface was determined from ringdown experiments. We measured the mechanical quality factor of three fused silica samples with Coatings deposited on them. The loss angle, ||(f), of the coating material for strains parallel to the coated surface was found to be 4.2 ± 0.3 × 10−4 for Coatings deposited on commercially polished slides, and 1.0 ± 0.3 × 10−4 for a coating deposited on a superpolished disc. Using these numbers, we estimate the effect of Coatings on thermal noise in the initial LIGO and Advanced LIGO interferometers. We also find that the corresponding prediction for thermal noise in the 40 m LIGO prototype at Caltech is consistent with the noise data. These results are complemented by results for a different type of coating, presented in a companion paper.
D R M Crooks - One of the best experts on this subject based on the ideXlab platform.
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thermal noise from Optical Coatings in gravitational wave detectors
Applied Optics, 2006Co-Authors: G M Harry, H Armandula, Eric D Black, D R M Crooks, G Cagnoli, J Hough, P G Murray, S Reid, S Rowan, P SneddonAbstract:Gravitational waves are a prediction of Einstein's general theory of relativity. These waves are created by massive objects, like neutron stars or black holes, oscillating at speeds appreciable to the speed of light. The detectable effect on the Earth of these waves is extremely small, however, creating strains of the order of 10−21. There are a number of basic physics experiments around the world designed to detect these waves by using interferometers with very long arms, up to 4 km in length. The next-generation interferometers are currently being designed, and the thermal noise in the mirrors will set the sensitivity over much of the usable bandwidth. Thermal noise arising from mechanical loss in the Optical Coatings put on the mirrors will be a significant source of noise. Achieving higher sensitivity through lower mechanical loss Coatings, while preserving the crucial Optical and thermal properties, is an area of active research right now.
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thermal noise in interferometric gravitational wave detectors due to dielectric Optical Coatings
Classical and Quantum Gravity, 2002Co-Authors: G M Harry, S Rowan, Andri M Gretarsson, P R Saulson, Scott E Kittelberger, Steven D Penn, William J Startin, Martin M Fejer, D R M CrooksAbstract:We report on thermal noise from the internal friction of dielectric Coatings made from alternating layers of Ta2O5 and SiO2 deposited on fused silica substrates. We present calculations of the thermal noise in gravitational wave interferometers due to Optical Coatings, when the material properties of the coating are different from those of the substrate and the mechanical loss angle in the coating is anisotropic. The loss angle in the Coatings for strains parallel to the substrate surface was determined from ringdown experiments. We measured the mechanical quality factor of three fused silica samples with Coatings deposited on them. The loss angle, ||(f), of the coating material for strains parallel to the coated surface was found to be 4.2 ± 0.3 × 10−4 for Coatings deposited on commercially polished slides, and 1.0 ± 0.3 × 10−4 for a coating deposited on a superpolished disc. Using these numbers, we estimate the effect of Coatings on thermal noise in the initial LIGO and Advanced LIGO interferometers. We also find that the corresponding prediction for thermal noise in the 40 m LIGO prototype at Caltech is consistent with the noise data. These results are complemented by results for a different type of coating, presented in a companion paper.
Detlev Ristau - One of the best experts on this subject based on the ideXlab platform.
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Production strategies for high-precision Optical Coatings
Optical Thin Films and Coatings, 2014Co-Authors: Henrik Ehlers, Detlev RistauAbstract:Abstract This chapter is dedicated to advanced monitoring and control concepts for deposition processes employed in the production of Optical Coatings. After a motivation before the background of recent challenges in Optical coating technologies and their application, an introduction will be given into implementations of Optical broadband monitoring concepts as well as related instruments to simulate deposition processes and to detect errors during a deposition run. Also, selected examples will be outlined to support the versatility of these novel approaches. Finally, a section will be concentrated on ternary oxides as material mixtures and rugate filters produced by co-deposition processes.
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quality control of oblique incidence Optical Coatings based on normal incidence measurement data
Optics Express, 2013Co-Authors: Tatiana V. Amotchkina, Michael K Trubetskov, Alexander V. Tikhonravov, Detlev Ristau, Henrik Ehlers, Sebastian Schlichting, David L Death, Robert J Francis, Vladimir PervakAbstract:We demonstrate selection of reliable approaches for post-production characterization of oblique incidence multilayer Optical Coatings. The approaches include choice of input information, selection of adequate coating model, corresponding numerical characterization algorithm, and verification of the results. Applications of the approaches are illustrated with post-production characterization of oblique incidence edge filter, oblique incidence beam splitter and oblique incidence 43-layer quarter-wave mirror.
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laser damage thresholds of Optical Coatings
Thin Solid Films, 2009Co-Authors: Detlev Ristau, Marco Jupe, Kai StarkeAbstract:Abstract Since the very beginning of laser technology, Laser Induced Damage Thresholds (LIDT) of Optical components were always an obstacle for the application of laser systems operating at high power levels. Also, further progresses in the development of new high power laser concepts are often directly limited by the availability of advanced Optical components with high quality and LIDT-values. Nowadays, in the course of the development of Optical materials with excellent quality and power handling capability, the problem of laser induced damage has shifted from the bulk to the surface of the Optical component. The Optical surface is objected to various production steps and environmental influences, which modify its structure and composition. Especially, the thin film coating, which is deposited on the Optical surface to adapt its reflectance and transmittance to the application, contributes predominantly to the reduction of the LIDT-values. As a consequence, the measurement and optimization of the power handling capability of thin films is considered as one of the primary research areas in modern optics technology and is supported by an extensive scientific community. In the present paper, a brief review will be given on selected fundamental damage mechanisms in thin films considering different operation conditions of modern laser systems. Also, the current standards for the measurement of LIDT will be described, and examples illustrating some practical aspects of high power Optical Coatings will be presented. Finally, recent trends in laser technology will be discussed in respect to research in laser induced damage.