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Study of behavior of the refractive index fluctuations to the lenght noise in displacement interferometry
Holá, Miroslava
Nanoscale measurement became one of the key challenges in the field of metrology in last ten years. The international project launched called “Nanotrace” where renowned EU laboratories including the proposer of this project were trying to break the limits of resolution in interferometry. Techniques investigated here have proven that there are chances to achieve significant improvements in resolution of laser interferometry. Measurement of position within a limited range is typical for coordinate measuring system such as nanometrology standards combining scanning probe microscopy (SPM) with precise positioning. In this contribution we evaluate the level of uncertainty associated with spatial shift of two measuring beams and spatial shift of one measuring beam (change of length the measuring beam). Consequently the nature of the fluctuations of the refractive index of air in laser interferometry is investigated anddiscussed with the focus on potential applications in coordinate measuring systems and long-range metrological scanning pro microscopy systems.
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Advanced Laser Measuring Systems in Nanometrology
Lazar, Josef ; Hrabina, Jan ; Holá, Miroslava ; Vychodil, M.
We present a development of a nanometrology system combining local probe microscopy and precise positioning and measuring in the nanoscale. The positioning operates in short range with a focus on precision; displacement measurement controls the sample stage in six degrees of freedom with high-resolution interferometry. The system is designed to operate as a national standard for nanometrology. The contribution presents collaborative work with Meopta company.
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Detection standing wave within Fabry-Perot Cavity
Holá, Miroslava
This contribution follows up with project Interferometry with compensation of the refractive index of air. This inteferometric technique was based on differential interferometry setup for measurement in the subnanometer scale in atmospheric conditions. One of the important limiting factor in any optical measurement are fluctuations of the refractive index of air representing a source of uncertainty on the 10-6 level when evaluated indirectly from the physical parameters of the atmosphere. Our proposal is based on the concept of overdetermined interferometric setup where the reference length is derived from a mechanical frame made from a material with very low thermal coefficient on the 1*E-8 level (Zerodur - Schott). The optical setup consists of three interferometers sharing the same beam path where two measurement differentially the displacement while the third evaluates the changes in the measuring range acting as a tracking refractometer. The concept of stabilization of wavelength against the mechanical reference is realized within passive Fabry-Perot cavity. The link between the wavelength and mechanical reference here is in principle simple, the laser optical frequency has to be locked to the resonance of the passive cavity either through tracking the transmission maximum or reflection minimum. The key component for position sensing inside of a passive Fabry-Perot cavity is low-loss transparent photodetector. The transparent photodetector made in cooperation with Institute of Physics of the ASCR - Department of Thin Films and Nanostructures (work group A. Fejfar). Transparent photodetector is made of fused silica substrate, active photo resistive silicon layer with side titanium electrode and a set of antireflection coatings optimized for minimum reflectivity. Optimized AR coating for 532 nm.
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Nanopositioning with detection of a standing wave
Holá, Miroslava ; Hrabina, Jan ; Číp, Ondřej ; Fejfar, A. ; Stuchlík, J. ; Kočka, J. ; Oulehla, Jindřich ; Lazar, Josef
A measuring technique is intended for displacement and position sensing over a limited range with detection of standing-wave pattern inside of a passive Fabry-Perot cavity. In this concept we consider locking of the laser optical frequency and the length of the Fabry-Perot cavity in resonance. Fixing the length of the cavity to e.g. a highly stable mechanical reference allows stabilizing wavelength of the laser in air and thus to eliminate especially the faster fluctuations of refractive index of air due to air flow and inhomogeneity. Detection of the interference maxima and minima within the Fabry-Perot cavity along the beam axis has been tested and proven with a low loss transparent photodetector with very low reflectivity. The transparent photodetector is based on a thin polycrystalline silicon layer. Reduction of losses was achieved thanks to a design as an optimized set of interference layers acting as an antireflection coating. The principle is demonstrated on an experimental setup.
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Interferometric coordinates measurement sytem for local probe microscopy nanometrology
Hrabina, Jan ; Lazar, Josef ; Klepetek, P. ; Číp, Ondřej ; Čížek, Martin ; Holá, Miroslava ; Šerý, Mojmír
We present an overview of new approaches to the design of nanometrology measuring system with a focus on methodology of nanometrology interferometric techniques and associated problems. The design and development of a nanopositioning setup with interferometric multiaxis monitoring and control involved for scanning probe microscopy techniques (primarily atomic force microscopy, AFM) for detection of the sample profile is presented. Coordinate position sensing allows upgrading the imaging microscope techniques up to quantified measuring. Especially imaging techniques in the micro- and nanoworld overcoming the barrier of resolution given by the wavelength of visible light are a suitable basis for design of measuring systems with the best resolution possible. The system is being developed in cooperation with the Czech metrology institute and it is intended to operate as a national nanometrology standard combining local probe microscopy techniques and sample position control with traceability to the primary standard of length.
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Precision displacement interferometry with stabilization of wavelength on air
Lazar, Josef ; Holá, Miroslava ; Hrabina, Jan ; Buchta, Zdeněk ; Číp, Ondřej
We present an interferometric technique based on differential interferometry setup for measurement in the subnanometer scale in atmospheric conditions. The motivation for development of this ultraprecise technique is coming from the field of nanometrology. The key limiting factor in any optical measurement are fluctuations of the refractive index of air representing a source of uncertainty on the 10'6 level when evaluated indirectly from the physical parameters of the atmosphere. Our proposal is based on the concept of overdetermined interferometric setup where a reference length is derived from a mechanical frame made from a material with very low thermal coefficient on the 1 O'8 level. The technique allows to track the variations of the refractive index of air on-line directly in the line of the measuring beam and to compensate for the fluctuations. The optical setup consists of three interferometers sharing the same beam path where two measure differentially the displacement while the third represents a reference for stabilization of the wavelength of the laser source. The principle is demonstrated on an experimental setup and a set of measurements describing the performance is presented.
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Differential interferometry with suppression of the influence of refractive index of air for nanometrology
Holá, Miroslava ; Číp, Ondřej ; Hrabina, Jan ; Buchta, Zdeněk ; Lazar, Josef
We present an interferometric technique based on differential interferometry setup for measurement in the subnanometer scale in atmospheric conditions. The motivation for development of this ultraprecise technique is coming from the field of nanometrology. The key limiting factor in any optical measurement are fluctuations of the refractive index of air representing a source of uncertainty on the 1*E-6 level when evaluated indirectly from the physical parameters of the atmosphere. Our proposal is based on the concept of overdetermined interferometric setup where a reference length is derived from a mechanical frame made from a material with very low thermal coefficient on the 1*E-8 level. The technique allows to track the variations of the refractive index of air on-line directly in the line of the measuring beam and to compensate for the fluctuations. The optical setup consists of three interferometers sharing the same beam path where two measure differentially the displacement while the third evaluates the changes in the measuring range acting as a tracking refractometer. The principle is demonstrated on an experimental setup and a set of measurements describing the performance is presented.
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Methodology of Solvency II and impacts on economy of insurance company
Černá, Eva ; Ducháčková, Eva (advisor) ; Holá, Miroslava (referee)
This diploma paper is concerned with new rules of regulation of insurance system. Their name is Solvency II. The aim of work is view of structure of new regime of insurance system and impacts of new rules on economy of insurance company. The work is divided into three parts, the first part is concerned with historical progress of regulation in the czech area and an activity of supervision. In the second part there is comparison of current rules for calculation of solvency with suggested methodology. There are contained structural elements of new metodology. The concept of Solvency II is inspired by rules for banks Basel II and therefore same and different characters are studied. The third part is engaged in possible impacts of new methodology of solvency on insurance market and economy of insurance company.
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Operačné riziko v bankách
Holá, Miroslava ; Dvořák, Petr (advisor) ; Tuček, Miroslav (referee)
Nové regulatórne pravidlá BASEL II, ktorých hlavným cieľom je zvýšiť bezpečnosť a stabilitu finančných systémov, posilniť konkurenciu medzi bankami a umožniť väčšiu rizikovú citlivosť definujú nový typ rizika, ktoré je potrebné pokryť dodatočným kapitálom - riziko operačné. BASEL II vymedzuje 3 prístupy (základný, štandardizovaný a pokročilý), ktoré je možné použiť k výpočtu regulatórneho kapitálu, potrebného na pokrytie strát vzniknutých v dôsledku realizácie operačného rizika. V prvej časti diplomovej práce je popísaný nový koncept bankovej regulácie, v časti druhej je vymedzený pojem operačné riziko a základné prístupy k jeho kvantifikácii. Tretia kapitola obsahuje návrh zjednodušeného teoretického modelu, ktorý umožní kapitálovú požiadavku na pokrytie operačného rizika kvantifikovať.
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