Угловые характеристики сенсора коэффициента преломления на основе отражательного интерферометра

The angular properties of sensor, implemented in Kretschmann’s scheme, where the optimized for oblique incidence of light thin-film reflection interferometer acts as a sensing element, are described in the paper. Analytical equations, defining the sensor’s properties for S and P polarization states at working wavelength in vicinity of working angle of incidence, are provided, as well as approximate equations for main parameters of sensor: sensitivity, angular full width at half maximum, contrast and figure of merit. The possibility to vary the named parameters by choosing appropriate metal and dielectric layers of the structure is shown. For an example, the numerical calculations are made for one of special cases, optimized for S polarization state, as having larger figures of merit. The dependencies of angular properties on number of layers and base thickness are demonstrated. It is shown, that angular measurements with this method are theoretically capable of infinite figures of merit, and in practice they are only limited by losses in layered structure and beam divergency. The recommendations for experimental realization of method are given.

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Proteins and direct methods

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1524/zkri.1991.197.3-4.197 ◽

1991 ◽

Vol 197 (3-4) ◽

Cited By ~ 7

Author(s):

Fan Hai-fu ◽

Hao Quan ◽

M. M. Woolfson

Keyword(s):

First Principles ◽

Figure Of Merit ◽

Direct Methods ◽

Large Structure ◽

Low Resolution ◽

Figures Of Merit ◽

Large Structures ◽

Resolution Data

AbstractConventional direct methods, which work so well for small structures, are less successful for macromolecules. Where it has been demonstrated that a solution might be found using direct methods it is then found that the usual figures of merit are unable to distinguish the few good sets of phases from the large number of sets generated. The reasons for the difficulties with very large structures are considered from a first-principles approach taking into account both the factors of having a large number of atoms and low resolution data. A proposal is made for trying to recognize good phase sets by taking a large structure as a sum of a number of smaller structures for each of which a conventional figure of merit can be applied.

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On The Application of SiO2/SiC Grating on Ag for High-Performance Fiber Optic Plasmonic Sensing of Cortisol Concentration

Materials ◽

10.3390/ma13071623 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1623 ◽

Cited By ~ 8

Author(s):

Ankit Kumar Pandey ◽

Anuj K. Sharma ◽

Carlos Marques

Keyword(s):

High Performance ◽

Figure Of Merit ◽

Fiber Optic ◽

Limit Of Detection ◽

Cortisol Concentration ◽

Practical Implementation ◽

Angle Of Incidence ◽

Plasmonic Sensor ◽

High Performance Fiber ◽

Better Than

This paper reports on high-accuracy simulation of a grating structure based fiber optic plasmonic sensor for salivary cortisol sensing. Gratings of SiO2 and SiC (one at a time) in combination with a thin Ag layer are considered to be in direct contact with analyte medium (solutions containing different concentrations of cortisol) considering that the groove regions are also filled with analyte. The optimization of Ag layer thickness is carried out to achieve maximum power loss (PL) corresponding to cortisol concentration variation. The variation of PL (in dB) spectra with the angle of incidence (α) is the sensing mechanism of the proposed scheme. Sensing performance is extensively analyzed in terms of sensitivity, limit-of-detection (LOD) and figure-of-merit (FOM) that incorporates both the sensitivity and the width of the corresponding PL curves. While the sensitivity and FOM values are significantly large, the results also reveal that in angular interrogation mode (AIM), an average LOD of 9.9 pg/mL and 9.8 pg/mL is obtained for SiO2 and SiC-based sensor designs, respectively. When the intensity interrogation method (IIM) in place of AIM is considered, an average LOD of 22.6 fg/mL and 68.17 fg/mL is obtained for SiO2 and SiC-based sensor designs, respectively. LOD (with IIM, in particular) is considerably better than the present-state-of-art related to cortisol monitoring. Pragmatic model for possible practical implementation of sensor scheme is also discussed. The involvement of optical fiber in the proposed sensor design makes it possible to implement it as a flexible sensor or for wearable solution for cortisol detection via sweat monitoring as well as for measuring cortisol level in aquaculture tanks where concentration levels are much lower than 10 ng/mL.

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The propagation of electromagnetic waves in a stratified medium

Mathematical Proceedings of the Cambridge Philosophical Society ◽

10.1017/s0305004100018600 ◽

1929 ◽

Vol 25 (1) ◽

pp. 97-120 ◽

Cited By ~ 50

Author(s):

D. R. Hartree

Keyword(s):

Refractive Index ◽

Reflection Coefficient ◽

Electromagnetic Waves ◽

Stratified Medium ◽

Simple Extension ◽

Angle Of Incidence ◽

First Approximation ◽

Special Cases ◽

Cartesian Coordinate ◽

The Given

The equations of propagation of electromagnetic waves in a stratified medium (i.e. a medium in which the refractive index is a function of one Cartesian coordinate only—in practice the height) are obtained first from Maxwell's equations for a material medium, and secondly from the treatment of the refracted wave as the sum of the incident wave and the wavelets scattered by the particles of the medium. The equations for the propagation in the presence of an external magnetic field are also derived by a simple extension of the second method.The significance of a reflection coefficient for a layer of stratified medium is discussed and a general formula for the reflection coefficient is found in terms of any two independent solutions of the equations of propagation in a given stratified medium.Three special cases are worked out, for waves with the electric field in the plane of incidence, viz.(1) A finite, sharply bounded, medium which is “totally reflecting” at the given angle of incidence.(2) Two media of different refractive index with a transition layer in which μ2 varies linearly from the value in one to the value in the other.(3) A layer in which μ2 is a minimum at a certain height and increases linearly to 1 above and below, at the same rate.For cases (2) and (3) curves are drawn showing the variation of reflection coefficient with thickness of the stratified layer.Case (3) may be of some importance as a first approximation to the conditions in the Heaviside layer.

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Reversed de Wolff figure of merit and its application to powder indexing solutions

Journal of Applied Crystallography ◽

10.1107/s0021889813018773 ◽

2013 ◽

Vol 46 (5) ◽

pp. 1277-1282 ◽

Cited By ~ 6

Author(s):

R. Oishi-Tomiyasu

Keyword(s):

Figure Of Merit ◽

Zero Point ◽

Figures Of Merit

Two new figures of merit for powder indexing solutions are proposed: the reversed figure of meritMnRevand the symmetric figure of meritMnSym. These are naturally suggested by the theory underlying the de Wolff figure of meritMn. Nevertheless,MnRevhas characteristics opposite to those ofMnwith regard to sensitivity to impurity peaks and extinct reflections.MnSymhas intermediate properties betweenMnandMnRev. Applications of the new figures of merit to powder indexing solutions and zero-point shift estimation are introduced. All of the figures of merit are available from the powder auto-indexing softwareConograph(http://sourceforge.jp/projects/conograph/; http://research.kek.jp/people/rtomi/ConographGUI/web_page.html).

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Thermal Ranges and Figures of Merit for Gold-Containing Precursors For ALD

10.26434/chemrxiv.13077386.v1 ◽

2020 ◽

Author(s):

Matthew Griffiths ◽

Zachary Dubrawski ◽

Peter Gordon ◽

Marcel Junige ◽

Sean Barry

Keyword(s):

Atomic Layer Deposition ◽

Chemical Vapour Deposition ◽

Figure Of Merit ◽

Vapour Deposition ◽

Chemical Vapour ◽

Thermal Characteristics ◽

Atomic Layer ◽

Figures Of Merit ◽

Layer Deposition

A survey of known gold-containing chemical vapour deposition (CVD) and atomic layer deposition (ALD) precursors, with a focus on collecting their volatilization and decomposition data. These data were applied to a figure of merit (σ) developed to easily assess the thermal characteristics.

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A Hybrid Thermal Energy Storage Device, Part 2: Thermal Performance Figures of Merit

Journal of Electronic Packaging ◽

10.1115/1.1646420 ◽

2004 ◽

Vol 126 (1) ◽

pp. 8-13 ◽

Cited By ~ 15

Author(s):

Ning Zheng ◽

R. A. Wirtz

Keyword(s):

Energy Storage ◽

Thermal Energy ◽

Thermal Energy Storage ◽

Figure Of Merit ◽

Design Procedure ◽

Storage Device ◽

Storage Unit ◽

Figures Of Merit ◽

Design Requirements ◽

Plate Type

Two figures of merit for hybrid Thermal Energy Storage (TES) units are developed: the volumetric figure of merit, V˜, and the temperature control figure of merit, ΔT˜. A dimensional analysis shows that these quantities are related to the performance specification of the storage unit and its physical design. A previously benchmarked semi-empirical finite volume model is used to study the characteristics of various plate-type TES-unit designs. A parametric study is used to create a database of optimal designs, which is then used to form simple correlations of V˜ and ΔT˜ in terms of design requirements and attributes. A preliminary design procedure utilizing these figures of merit is suggested. Sample calculations show that these correlations can be used to quickly determine the design attributes of a plate-type TES-unit, given design requirements.

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An optical examination of thin films. I.—The optical constants of mercury

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1934.0085 ◽

1934 ◽

Vol 145 (854) ◽

pp. 115-126 ◽

Cited By ~ 17

Keyword(s):

Thin Films ◽

Refractive Index ◽

Optical Constants ◽

Relative Phase ◽

Reflection Coefficients ◽

Angle Of Incidence ◽

Clean Surface ◽

Phase Retardation ◽

Optical Examination ◽

Approximate Equations

Drude originally suggested that the properties of films on both absorbing and non-absorbing substrates could be studied by an optical method, since the reflecting properties of a surface are modified by the presence of a film. This method has in part been used by various workers, with some success. For liquid surfaces, or for smooth surfaces of solids, such as are obtained by cleavage or after suitable polishing, it is possible to measure “the relative phase retardation,” Δ, and “the ratio of the reflection coefficients,” tan ψ, which define the reflecting properties. From the values of Δ and ψ for a clean surface, the refractive index, n , and the absorption coefficient, k , characteristic of the material can be found from the approximate equations n = sin ϕ tan ϕ cos 2ψ/(1 + cos Δ sin 2ψ), (1.1) k = sin Δ tan 2ψ, (2.1) where ϕ is the angle of incidence.

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Reflection of Dilatational Waves at the Edge of a Plate

Journal of Applied Mechanics ◽

10.1115/1.4011499 ◽

1957 ◽

Vol 24 (2) ◽

pp. 219-227

Author(s):

T. R. Kane

Keyword(s):

Shear Wave ◽

Plane Stress ◽

Plate Theory ◽

Angle Of Incidence ◽

Two Dimensional ◽

Arbitrary Angle ◽

Reflected Waves ◽

Dilatational Wave ◽

Special Cases

Abstract The reflection of straight-crested dilatational waves at the edge of a semi-inflnite plate is studied in terms of a two-dimensional plate theory and in terms of the theory of generalized plane stress. It is found that, in general, a dilatational wave propagated toward the edge at an arbitrary angle of incidence gives rise to three reflected waves; namely, two dilatational waves and a shear wave. A number of special cases are investigated in detail.

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An optimum design for a time-of-flight neutron diffractometer for measuring engineering stresses

Journal of Applied Crystallography ◽

10.1107/s002188980101891x ◽

2002 ◽

Vol 35 (1) ◽

pp. 49-57 ◽

Cited By ~ 41

Author(s):

Michael W. Johnson ◽

Mark R. Daymond

Keyword(s):

Figure Of Merit ◽

Time Of Flight ◽

Peak Position ◽

Shape Parameters ◽

Gaussian Peak ◽

Figures Of Merit ◽

Neutron Diffractometer ◽

Ceramic Components ◽

Non Gaussian ◽

First Time

A method is described for optimizing the design of a time-of-flight neutron diffractometer designed to measure lattice parameters. Such diffractometers are now used extensively by engineers and materials scientists for measuring strain within metallic and ceramic components. The method presented relies on the identification of a figure of merit (FOM) that accurately describes the performance of such an instrument. For the first time, an FOM for an instrument exhibiting non-Gaussian peak shapes is described, and the methods by which this FOM may be maximized are described. Although the instrument described is based on the time-of-flight technique, the FOM derived may equally well be used to optimize a reactor-based instrument. While measuring peak position is a straightforward example, it is shown that similar figures of merit may be found for other peak shape parameters, and thus other types of instrumentation.

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