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Unusual optical anisotropy was experimentally observed in hexagonal boron nitride thin films produced from bulk boron nitride via ultrasonication. Both the linear and circular polarisation demonstrated a well-defined single axis of anisotropy over a large sample area. To understand this phenomenon, we employed statistical analysis of optical microscopy images and atomic force microscopy to reveal an ordered particle density distribution at the microscopic level corresponding to the optical axis observed in the polarisation data. The direction of the observed ordering matched the axis of anisotropy. Hence, we attribute the measured optical anisotropy of the thin films to microscopic variations in the particle density distribution.

Despite several decades of active experimental and theoretical studies of rare-earth or-thoferrites, the mechanism of the formation of their specific magnetic, magnetoelastic, optical, and magneto-optical properties remains a subject of discussion. This paper provides an overview of sim-ple theoretical model approaches to quantitatively describing the structure–property relationships—in particular, the interplay between FeO6 octahedral deformations/rotations and the main magnetic and optic characteristics, such as Néel temperature, overt and hidden canting of magnetic sublattices, magnetic and magnetoelastic anisotropy, and optic and photoelastic anisotropy. © 2021 by the author. Licensee MDPI, Basel, Switzerland.

Thin hexagonal boron nitride films with a thickness of several monoatomic layers have been manufactured by splitting of bulk samples in an ultrasonic bath. The transmission, reflection, and photoluminescence spectra of such films are studied. The spectral dependences of linear and circular polarization of light passing through the sample are measured. Scanning electron microscopy investigation demonstrates homogeneity of the obtained samples. However, investigation of Stokes parameters of light passing through the sample makes it possible to reveal hidden anisotropy of optical properties of these films.

The paper presents the structural-logical diagram and research design of the newest method of 3D Mueller-matrix microscopy of the layer-by-layer structure of the polycrystalline component [1-9] of depolarizing histological sections of the brain. Principles of differential diagnosis of the formation of hemorrhages of traumatic genesis, cerebral infarction ischemic and hemorrhagic genesis by the method of 3D Mueller-matrix microscopy. Layer-by-layer azimuthal-invariant Mueller-matrix images of circular birefringence (MMI OA) of histological brain sections and operational characteristics of the method of their statistical analysis were determined.

In order to produce three-dimensional components from metals, a wide variety of processes exist. Laser processes combined with metal powders are frequently used and developed. Restrictive factors are the machine-related small workspace, the machinery costs and the material portfolio, which place the technology in the area of high-performance components. Wire and arc additive manufacturing (WAAM), as a robust and economical welding process technology in combination with robot applications, represents an option to become more size-independent and provides variability in the range of materials. This work shows results for the robot-based WAAM of structures made from nickel alloy 617. The main focus of the investigation was the determination of the mechanical properties in the as-welded state for which static strength tests, microhardness and metallographic studies were carried out. The anisotropic material behaviour in relation to the build direction (BD) was tested. The direction-dependent strength properties of single-track welded structures are presented with samples taken and tested at 0°, 45° and 90° to the BD. The deformation behaviour was investigated by micro-tensile tests in a scanning electron microscope, whereby the formation of sliding steps on the polished surface under tensile stress was studied. The anisotropic behaviour of the WAAM structures is discussed under consideration of the microstructure and with regard to the grain size development and phase formation. The results indicate an anisotropic material behaviour in the as-welded state based of the crystallographic orientation of the material. © 2020, The Author(s).

We introduce a method of azimuthally invariant 3D Mueller-matrix (MM) layer-by-layer mapping of the phase and amplitude parameters of anisotropy of the partially depolarizing layers of benign (adenoma) and malignant (carcinoma) prostate tumours. The technique is based on the analysis of spatial variations of Mueller matrix invariant (MMI) of histological sections of benign (adenoma) and malignant (carcinoma) tissue samples. The phase dependence of magnitudes of the first-to-fourth order statistical moments is applied to characterize 3D spatial distributions of MMI of linear and circular birefringence and dichroism of prostate tumours. The high order statistical moments and phase sections of the optimal differentiation of the polycrystalline structure of tissue samples are revealed. The obtained results are compared with the results obtained by conventional methods utilizing polarized light, including 2D and 3D Mueller matrix imaging.

Since recently, a number of innovative polarization-based optical imaging modalities have been introduced and extensively used in various biomedical applications, with an ultimate aim to attain the practical tool for the optical biopsy and functional characterization of biological tissues. The techniques utilize polarization properties of light and Mueller matrix mapping of microscopic images of histological sections of biological tissues or polycrystalline films of biological fluids. The main drawback of currently developed laser polarimetry approaches and Mueller matrix mapping techniques is poor reproducibility of experimental data. This is due to azimuthal dependence of polarization and ellipticity values of most matrix elements to sample orientation in respect to incidence light polarization. Current study aims to generalize the methods of laser polarimetry for diagnosis of partially depolarizing optically anisotropic biological tissues. A method of differential Mueller matrix mapping for reconstruction of linear and circular birefringence and dichroism parameter distributions of partially depolarizing layers of biological tissues of different morphological structure is introduced and practically implemented. The coordinate distributions of the value of the first-order differential matrix elements of histological sections of brain tissue with spatially structured, optically anisotropic fibrillar network, as well as of parenchymatous tissue of the rectum wall with an “islet” polycrystalline structure are determined. Within the statistical analysis of polarization reproduced distributions of the averaged parameters of phase and amplitude anisotropy, the significant sensitivity of the statistical moments of the third and fourth orders to changes in the polycrystalline structure of partially depolarizing layers of biological tissue is observed. The differentiation of female reproductive sphere connective tissue is realized with excellent accuracy. The diff

In order to produce three-dimensional components from metals, a wide variety of processes exist. Laser processes combined with metal powders are frequently used and developed. Restrictive factors are the machine-related small workspace, the machinery costs and the material portfolio, which place the technology in the area of high-performance components. Wire and arc additive manufacturing (WAAM), as a robust and economical welding process technology in combination with robot applications, represents an option to become more size-independent and provides variability in the range of materials. This work shows results for the robot-based WAAM of structures made from nickel alloy 617. The main focus of the investigation was the determination of the mechanical properties in the as-welded state for which static strength tests, microhardness and metallographic studies were carried out. The anisotropic material behaviour in relation to the build direction (BD) was tested. The direction-dependent strength properties of single-track welded structures are presented with samples taken and tested at 0°, 45° and 90° to the BD. The deformation behaviour was investigated by micro-tensile tests in a scanning electron microscope, whereby the formation of sliding steps on the polished surface under tensile stress was studied. The anisotropic behaviour of the WAAM structures is discussed under consideration of the microstructure and with regard to the grain size development and phase formation. The results indicate an anisotropic material behaviour in the as-welded state based of the crystallographic orientation of the material. © 2020, The Author(s).

The study was devoted to optical characterization of non-stoichiometric silicon nitride films prepared by reactive magnetron sputtering in argon-nitrogen atmosphere onto cold (unheated) substrates. It was found that these films exhibit the combination of three defects: optical inhomogeneity (refractive index profile across the films), uniaxial anisotropy with the optical axis perpendicular to the boundaries and random roughness of the upper boundaries. The influence of the uniaxial anisotropy was included into the corresponding formulae of the optical quantities using the matrix formalism and the approximation of the inhomogeneous layer by a multilayer system consisting of large number thin homogeneous layers. The random roughness was described using the scalar diffraction theory. The processing of the experimental data was performed using the multi-sample modification of the least-squares method, in which experimental data of several samples differing in thickness were processed simultaneously. The dielectric response of the silicon nitride films was modeled using the modification of the universal dispersion model, which takes into account absorption processes corresponding to valence-to-conduction band electron transitions, excitonic effects and Urbach tail. The spectroscopic reflectometric and ellipsometric measurements were supplemented by measuring the uniformity of the samples using imaging spectroscopic reflectometry of the samples using imaging spectroscopic reflectometry., Je studována optická charakterizace nestechiometrických vrstev nitridu křemíku připravených reaktivním magnetronovým naprašováním na chladné (nezahřívané) podložky v argonové – dusíkově atmosféře. Bylo zjištěno, že tyto vrstvy vykazují kombinaci tří defektů: optické nehomogenity (profil indexu lomu napříč vrstvami), jednoosé anizotropie s optickou osou kolmou k rozhraním a náhodné drsnosti horních rozhraní. Vliv jednoosé anizotropie byl zahrnut do odpovídajících vzorců pro optické veličiny užitím maticového formalizmu a aproximací nehomogenní vrstvy mnohavrstevným systémem velkého počtu tenkých homogenních vrstev. Náhodná drsnost byla popsána v rámci skalární teorie difrakce. Zpracování experimentálních dat bylo provedeno užitím mnohavzorkové modifikace metody nejmenších čtverců, ve které byla experimentální data několika vzorků lišících se v tloušťce zpracovávána současně. Dielektrická odezva studovaných vrstev byla modelována pomocí modifikace univerzálního disperzního modelu, který bere v úvahu absorpční procesy odpovídající elektronovým přechodům mezi valenčním a vodivostním pásem, exitačním procesům a Urbachovu konci. Spektroskopická reflektometrická a elipsometrická měření byla doplněna měřením uniformity vzorků pomocí zobrazovací spektroskopické reflektometrie.

The study was devoted to optical characterization of non-stoichiometric silicon nitride films prepared by reactive magnetron sputtering in argon-nitrogen atmosphere onto cold (unheated) substrates. It was found that these films exhibit the combination of three defects: optical inhomogeneity (refractive index profile across the films), uniaxial anisotropy with the optical axis perpendicular to the boundaries and random roughness of the upper boundaries. The influence of the uniaxial anisotropy was included into the corresponding formulae of the optical quantities using the matrix formalism and the approximation of the inhomogeneous layer by a multilayer system consisting of large number thin homogeneous layers. The random roughness was described using the scalar diffraction theory. The processing of the experimental data was performed using the multi-sample modification of the least-squares method, in which experimental data of several samples differing in thickness were processed simultaneously. The dielectric response of the silicon nitride films was modeled using the modification of the universal dispersion model, which takes into account absorption processes corresponding to valence-to-conduction band electron transitions, excitonic effects and Urbach tail. The spectroscopic reflectometric and ellipsometric measurements were supplemented by measuring the uniformity of the samples using imaging spectroscopic reflectometry of the samples using imaging spectroscopic reflectometry., Je studována optická charakterizace nestechiometrických vrstev nitridu křemíku připravených reaktivním magnetronovým naprašováním na chladné (nezahřívané) podložky v argonové – dusíkově atmosféře. Bylo zjištěno, že tyto vrstvy vykazují kombinaci tří defektů: optické nehomogenity (profil indexu lomu napříč vrstvami), jednoosé anizotropie s optickou osou kolmou k rozhraním a náhodné drsnosti horních rozhraní. Vliv jednoosé anizotropie byl zahrnut do odpovídajících vzorců pro optické veličiny užitím maticového formalizmu a aproximací nehomogenní vrstvy mnohavrstevným systémem velkého počtu tenkých homogenních vrstev. Náhodná drsnost byla popsána v rámci skalární teorie difrakce. Zpracování experimentálních dat bylo provedeno užitím mnohavzorkové modifikace metody nejmenších čtverců, ve které byla experimentální data několika vzorků lišících se v tloušťce zpracovávána současně. Dielektrická odezva studovaných vrstev byla modelována pomocí modifikace univerzálního disperzního modelu, který bere v úvahu absorpční procesy odpovídající elektronovým přechodům mezi valenčním a vodivostním pásem, exitačním procesům a Urbachovu konci. Spektroskopická reflektometrická a elipsometrická měření byla doplněna měřením uniformity vzorků pomocí zobrazovací spektroskopické reflektometrie.

The study was devoted to optical characterization of non-stoichiometric silicon nitride films prepared by reactive magnetron sputtering in argon-nitrogen atmosphere onto cold (unheated) substrates. It was found that these films exhibit the combination of three defects: optical inhomogeneity (refractive index profile across the films), uniaxial anisotropy with the optical axis perpendicular to the boundaries and random roughness of the upper boundaries. The influence of the uniaxial anisotropy was included into the corresponding formulae of the optical quantities using the matrix formalism and the approximation of the inhomogeneous layer by a multilayer system consisting of large number thin homogeneous layers. The random roughness was described using the scalar diffraction theory. The processing of the experimental data was performed using the multi-sample modification of the least-squares method, in which experimental data of several samples differing in thickness were processed simultaneously. The dielectric response of the silicon nitride films was modeled using the modification of the universal dispersion model, which takes into account absorption processes corresponding to valence-to-conduction band electron transitions, excitonic effects and Urbach tail. The spectroscopic reflectometric and ellipsometric measurements were supplemented by measuring the uniformity of the samples using imaging spectroscopic reflectometry of the samples using imaging spectroscopic reflectometry., Je studována optická charakterizace nestechiometrických vrstev nitridu křemíku připravených reaktivním magnetronovým naprašováním na chladné (nezahřívané) podložky v argonové – dusíkově atmosféře. Bylo zjištěno, že tyto vrstvy vykazují kombinaci tří defektů: optické nehomogenity (profil indexu lomu napříč vrstvami), jednoosé anizotropie s optickou osou kolmou k rozhraním a náhodné drsnosti horních rozhraní. Vliv jednoosé anizotropie byl zahrnut do odpovídajících vzorců pro optické veličiny užitím maticového formalizmu a aproximací nehomogenní vrstvy mnohavrstevným systémem velkého počtu tenkých homogenních vrstev. Náhodná drsnost byla popsána v rámci skalární teorie difrakce. Zpracování experimentálních dat bylo provedeno užitím mnohavzorkové modifikace metody nejmenších čtverců, ve které byla experimentální data několika vzorků lišících se v tloušťce zpracovávána současně. Dielektrická odezva studovaných vrstev byla modelována pomocí modifikace univerzálního disperzního modelu, který bere v úvahu absorpční procesy odpovídající elektronovým přechodům mezi valenčním a vodivostním pásem, exitačním procesům a Urbachovu konci. Spektroskopická reflektometrická a elipsometrická měření byla doplněna měřením uniformity vzorků pomocí zobrazovací spektroskopické reflektometrie.

The study was devoted to optical characterization of non-stoichiometric silicon nitride films prepared by reactive magnetron sputtering in argon-nitrogen atmosphere onto cold (unheated) substrates. It was found that these films exhibit the combination of three defects: optical inhomogeneity (refractive index profile across the films), uniaxial anisotropy with the optical axis perpendicular to the boundaries and random roughness of the upper boundaries. The influence of the uniaxial anisotropy was included into the corresponding formulae of the optical quantities using the matrix formalism and the approximation of the inhomogeneous layer by a multilayer system consisting of large number thin homogeneous layers. The random roughness was described using the scalar diffraction theory. The processing of the experimental data was performed using the multi-sample modification of the least-squares method, in which experimental data of several samples differing in thickness were processed simultaneously. The dielectric response of the silicon nitride films was modeled using the modification of the universal dispersion model, which takes into account absorption processes corresponding to valence-to-conduction band electron transitions, excitonic effects and Urbach tail. The spectroscopic reflectometric and ellipsometric measurements were supplemented by measuring the uniformity of the samples using imaging spectroscopic reflectometry of the samples using imaging spectroscopic reflectometry., Je studována optická charakterizace nestechiometrických vrstev nitridu křemíku připravených reaktivním magnetronovým naprašováním na chladné (nezahřívané) podložky v argonové – dusíkově atmosféře. Bylo zjištěno, že tyto vrstvy vykazují kombinaci tří defektů: optické nehomogenity (profil indexu lomu napříč vrstvami), jednoosé anizotropie s optickou osou kolmou k rozhraním a náhodné drsnosti horních rozhraní. Vliv jednoosé anizotropie byl zahrnut do odpovídajících vzorců pro optické veličiny užitím maticového formalizmu a aproximací nehomogenní vrstvy mnohavrstevným systémem velkého počtu tenkých homogenních vrstev. Náhodná drsnost byla popsána v rámci skalární teorie difrakce. Zpracování experimentálních dat bylo provedeno užitím mnohavzorkové modifikace metody nejmenších čtverců, ve které byla experimentální data několika vzorků lišících se v tloušťce zpracovávána současně. Dielektrická odezva studovaných vrstev byla modelována pomocí modifikace univerzálního disperzního modelu, který bere v úvahu absorpční procesy odpovídající elektronovým přechodům mezi valenčním a vodivostním pásem, exitačním procesům a Urbachovu konci. Spektroskopická reflektometrická a elipsometrická měření byla doplněna měřením uniformity vzorků pomocí zobrazovací spektroskopické reflektometrie.

This pilot study uses a Landau-Lifshitz phase field model to study the growth of a precipitate originating from a crack tip. A boundary layer giving a remote square root singular elastic stress field is applied. The materials are assumed to be elastic-plastic with linear strain hardening. The precipitate is assumed to expand in a simplified anisotropic manner, meaning that the hydride is assumed to grow with an orientation giving maximum expansion perpendicular to the crack plane. The results show that the anisotropic expansion has a strong effect on the shape of the hydride. For anisotropic materials the hydride becomes wedge like. The resulting shapes for the anisotropic cases are in line with observations of internal crack tip hydrides in zirconium. The shapes resemble earlier results for Einstein-Smoluchowski stress driven diffusion using discrete models and simplified modelling of the growth process. The crack tip shielding caused by both precipitation and plastic yielding is examined using the J integral. It shows that the near tip value is a around a quarter of its remote value for elastic isotropic materials and around a half for anisotropic materials. © 2019 Elsevier Ltd

Structured surfaces enhance the functionality of components. Well known is the influence of the surface structure on friction and wear behavior. Beyond this, structured surfaces are widely used for various purposes such as optical, biological or mechanical applications. Therefore, the characterization of structured surfaces and surface features becomes increasingly important. The functionality of a surface can either be tested directly or indirectly. Due to the correlation of geometric surface features and its functionality, an indirect and self-evident way is by measuring the surface topography. To obtain the geometric essentials of these features, they need to be separated from the raw surface data. The standard procedure of decomposing a surface topography is by the use of a Gaussian filter bank, gaining so called scale-limited surfaces. This procedure shows drawbacks when characterizing structured surfaces by introducing distortions to the feature boundaries. To overcome these limitations, this work proposes the use of an automatic nonlinear anisotropic diffusion filter as an initial step to separate the features from the residual surface topography because of its edge preserving properties. It is shown that the nonlinear anisotropic diffusion serves well the separation of the features and their geometrical characterization.

Background: Using optical techniques for tissue diagnostics (so-called ‘optical biopsy’) has been a subject of extensive research for many years. Various groups have been exploring different spectral and/or imaging modalities (e.g. diffuse reflectance spectroscopy, autofluorescence, Raman spectroscopy, optical coherence tomography (OCT), polarized light microscopy, etc.) for biomedical applications. In this paper, we report on using multi-wavelength imaging Mueller polarimetry combined with an appropriated image post-processing for the detection of tissue malignancy. Methods: We investigate a possibility of complementary analysis of Mueller matrix images obtained for turbid tissue-like scattering phantoms and excised human normal and cancerous colorectal tissue samples embedded in paraffin. Combined application of correlation, fractal and statistical analysis was employed to assess quantitatively the polarization-inhomogeneous scattered fields observed at the surface of tissue samples. Results: The combined analysis of the polarimetric images of paraffin-embedded tissue blocks has proved to be an efficient tool for the unambiguous detection of tissue malignant transformation. A fractal structure was clearly observed at spatial distributions of depolarization of light scattered in healthy tissues in a visible range of spectrum, while corresponding distributions for cancerous tissues did not show such dependence. We demonstrate that paraffin does not destroy a fractal structure of spatial distribution of depolarization. Thus, the loss of fractality in spatial distributions of depolarization for cancerous tissue is related to the structural changes in the tissue sample induced by cancer itself and, therefore, may serve as a marker of the disease. Conclusions: The obtained results emphasize that a combined use of statistical, correlation and fractal analysis for the Mueller-matrix image post-processing is an effective approach for an assessment of variations of

Poly-3-hexylthiophene (P3HT) nanofibers are 1D crystalline semiconducting nanostructures, which are known for their application in photovoltaics. Due to the internal arrangement, P3HT nanofibers possess optical anisotropy, which can be enhanced on a macroscale if nanofibers are aligned. Alternating electric field, applied to a solution with dispersed nanofibers, causes their alignment and serves as a method to produce solid layers with ordered nanofibers. The transmission ellipsometry measurements demonstrate the dichroic absorption and birefringence of ordered nanofibers in a wide spectral range of 400–1700 nm. Moreover, the length of nanofibers has a crucial impact on their degree of alignment. Using electric birefringence technique, it is shown that external electric field applied to the solution with P3HT nanofibers can cause direct birefringence modulation. Dynamic alignment of dispersed nanofibers changes the refractive index of the solution and, therefore, the polarization of transmitted light. A reversible reorientation of nanofibers is organized by using a quadrupole configuration of poling electrodes. With further development, the described method can be used in the area of active optical fiber components, lab-on-chip or sensors. It also reveals the potential of 1D conducting polymeric structures as objects whose highly anisotropic properties can be implemented in electro-optical applications.​, QC 20161128

For flexible polymers, the deviatoric parts of the stress and optical anisotropy tensors, with the latter reflecting the orientational anisotropy of the monomeric segments, are proportional to each other. This proportionality, known as the stress-optical rule (SOR), is valid not only in the linear viscoelastic regime but also in the moderately nonlinear regime, given that the chain is not highly stretched and is free from the finite extensible nonlinear elasticity (FENE) effect. On start-up of flow in such a moderately nonlinear regime, the chain exhibits an overshoot of the shear stress and thus of the shear component of the segmental orientational anisotropy. Nevertheless, it was not clearly understood whether this overshoot is associated with an overshoot of chain stretch. This study revisited SOR to conduct a simple analysis for this problem. It turned out that the orientational anisotropy of subchains overshoots but the subchain stretch (identical to the chain stretch) does not when the shear stress overshoots in the moderately nonlinear regime.

When the optical behavior of light in a medium depends on the direction in which light is traveling, the medium is called optically anisotropic. Light is an electromagnetic wave and in this thesis, we discuss the electromagnetic theory on optical anisotropy. We do this with the assumption that the wavelength of light approaches zero. The field in optics in which this approach is applied is called geometrical optics. Then the wave character of light is not taken into account. In addition, we define a light wave as a set of rays, each with a certain direction and polarization state. The polarization state of a light ray defines the direction and the phase of the oscillating electric field of the light. In general, the light path of a light ray in an anisotropic medium depends on both the direction and the polarization state. The study of optical systems by means of calculating ray paths of polarized light rays is called polarized ray tracing. Optical anisotropy in the geometrical-optics approach is a classical problem, and most of the theory has been known for more than a century. Since the 1970s optical anisotropy is frequently discussed in the literature due to the rapid advances in liquid-crystal applications, such as the Liquid-Crystal Display (LCD). Liquid crystal is attractive for high-tech applications since it has the material properties of a fluid and the optical properties of an anisotropic crystal. Moreover, the optical properties of liquid crystal can be controlled with electric or magnetic fields. In the past few years Philips Research has had several activities in the field of liquid crystal. Novel liquid-crystal devices and applications have been investigated and developed into proof-of-principle demonstration models. In 2004 Philips Research introduced an auto-stereoscopic display technique based on liquid-crystal technology. Other examples are liquid-crystal-based backlight architectures for LCDs, liquid-crystal lenses and beam steering devices. Most, TNW Optics Research Group, Delft University of Technology

When the optical behavior of light in a medium depends on the direction in which light is traveling, the medium is called optically anisotropic. Light is an electromagnetic wave and in this thesis, we discuss the electromagnetic theory on optical anisotropy. We do this with the assumption that the wavelength of light approaches zero. The field in optics in which this approach is applied is called geometrical optics. Then the wave character of light is not taken into account. In addition, we define a light wave as a set of rays, each with a certain direction and polarization state. The polarization state of a light ray defines the direction and the phase of the oscillating electric field of the light. In general, the light path of a light ray in an anisotropic medium depends on both the direction and the polarization state. The study of optical systems by means of calculating ray paths of polarized light rays is called polarized ray tracing. Optical anisotropy in the geometrical-optics approach is a classical problem, and most of the theory has been known for more than a century. Since the 1970s optical anisotropy is frequently discussed in the literature due to the rapid advances in liquid-crystal applications, such as the Liquid-Crystal Display (LCD). Liquid crystal is attractive for high-tech applications since it has the material properties of a fluid and the optical properties of an anisotropic crystal. Moreover, the optical properties of liquid crystal can be controlled with electric or magnetic fields. In the past few years Philips Research has had several activities in the field of liquid crystal. Novel liquid-crystal devices and applications have been investigated and developed into proof-of-principle demonstration models. In 2004 Philips Research introduced an auto-stereoscopic display technique based on liquid-crystal technology. Other examples are liquid-crystal-based backlight architectures for LCDs, liquid-crystal lenses and beam steering devices. Most, TNW Optics Research Group, Delft University of Technology

Efficient alignment of aqueous carboxyl-functionalized multiwalled carbon nanotubes having remanent iron catalyst particles are carried out in relatively low external magnetic fields (B <= 1017 mT). The nanotubes were grown by catalytic chemical vapor deposition and then functionalized in a multistep oxidation process using nitric acid and potassium permanganate. In the field-induced ordering, the ferromagnetic property of iron nanoparticles entrapped in the inner-tubular cavity of nanotubes is exploited. Considerable dichroism of nanotube solutions (up to 3.02) is measured and deposition of aligned CNT networks from the solutions on silicon substrates is demonstrated., QC 20100525

Cholesteric liquid crystals doped with high clearing temperature azobenzene liquid crystals are shown to possess large, fast, and reversible dynamic photosensitive features. Selective wavelengths shifts approaching 400 nm are reported and depending on the host cholesteric liquid crystal, both red-shifted and blue-shifted wavelength changes can be induced. The photoinduced states of these material systems are shown to be stable for long periods of time upon removal of the radiation source, completely reversible, and dynamically fast. These phototunable features were demonstrated using both CW and nanosecond laser beams. The latter was used to change the selective reflection wavelength from blue to green with a single nanosecond pulse and the ability to write information into these films using these processes were demonstrated., Journal article submitted to Advanced Functional Materials. Prepared in collaboration with Beam Engineering for Advanced Measurements Co., Winter Park, FL.

The present invention provides a method of forming a polarizing material comprising exposing a layer of dichroic material to activating light illumination to provide an ordered structure with a distinguished absorption axis and thus photo-induce polarization, and fixing the induced polarization by polymerisation of the dichroic layer. The present invention also provides novel polarizing materials formed thereby. By selectively exposing regions of the dichroic material to differing activating radiation, different regions with different polarization axes can be created. The polarizing material can also be provided with a coating or coatings to alter the spectral response, and a stack formed of a plurality if dichroic layers may be provided.

The present invention provides a method of forming a polarizing material comprising exposing a layer of dichroic material to activating light illumination to provide an ordered structure with a distinguished absorption axis and thus photo-induce polarization, and fixing the induced polarization by polymerisation of the dichroic layer. The present invention also provides novel polarizing materials formed thereby. By selectively exposing regions of the dichroic material to differing activating radiation, different regions with different polarization axes can be created. The polarizing material can also be provided with a coating or coatings to alter the spectral response, and a stack formed of a plurality if dichroic layers may be provided.

In the general case the optical tensor of a nematic liquid crystal consists of nine nonzero elements, which makes it difficult to calculate light propagation in a liquid-crystal cell. For a two-dimensional (2-D) problem with TM polarization and a parallel liquid-crystal orientation where the molecules are only tilted and not twisted, the full problem can be calculated by using one magnetic field component, thus reducing the problem to a scalar one. This geometry is used to simulate the self-focusing effect which can lead to the generation of spatial optical solitary waves. This self-focusing occurs due to the optical nonlinear effect of field-induced director reorientation. Due to nondiagonal elements of the optical tensor, however, it is expected that the Poynting vector will deviate from the original propagation direction. Our simulations reveal that, in this case, the deviation will not cause the loss of the soliton-like beam propagation regime, but will rather give rise to a transverse undulating behaviour. © Springer 2005., SCOPUS: cp.j, info:eu-repo/semantics/published

In the general case the optical tensor of a nematic liquid crystal consists of nine nonzero elements, which makes it difficult to calculate light propagation in a liquid-crystal cell. For a two-dimensional (2-D) problem with TM polarization and a parallel liquid-crystal orientation where the molecules are only tilted and not twisted, the full problem can be calculated by using one magnetic field component, thus reducing the problem to a scalar one. This geometry is used to simulate the self-focusing effect which can lead to the generation of spatial optical solitary waves. This self-focusing occurs due to the optical nonlinear effect of field-induced director reorientation. Due to nondiagonal elements of the optical tensor, however, it is expected that the Poynting vector will deviate from the original propagation direction. Our simulations reveal that, in this case, the deviation will not cause the loss of the soliton-like beam propagation regime, but will rather give rise to a transverse undulating behaviour. © Springer 2005.

In the general case the optical tensor of a nematic liquid crystal consists of nine nonzero elements, which makes it difficult to calculate light propagation in a liquid-crystal cell. For a two-dimensional (2-D) problem with TM polarization and a parallel liquid-crystal orientation where the molecules are only tilted and not twisted, the full problem can be calculated by using one magnetic field component, thus reducing the problem to a scalar one. This geometry is used to simulate the self-focusing effect which can lead to the generation of spatial optical solitary waves. This self-focusing occurs due to the optical nonlinear effect of field-induced director reorientation. Due to nondiagonal elements of the optical tensor, however, it is expected that the Poynting vector will deviate from the original propagation direction. Our simulations reveal that, in this case, the deviation will not cause the loss of the soliton-like beam propagation regime, but will rather give rise to a transverse undulating behaviour. © Springer 2005., SCOPUS: cp.j, info:eu-repo/semantics/published

Photo-induced electric current modulation is studied in AFI-SWCNs systems by visible and near infra-red laser light at room temperature. Remarkable polarization anisotropy in the modulation is observed. lambda-dependence of the polarization anisotropy is analyzed by a simple model based on the optical anisotropy observed in absorption spectra. (C) 2002 Elsevier Science B.V. All rights reserved.

Photo-induced electric current modulation is studied in AFI-SWCNs systems by visible and near infra-red laser light at room temperature. Remarkable polarization anisotropy in the modulation is observed. lambda-dependence of the polarization anisotropy is analyzed by a simple model based on the optical anisotropy observed in absorption spectra. (C) 2002 Elsevier Science B.V. All rights reserved.

Photo-induced electric current modulation is studied in AFI-SWCNs systems by visible and near infra-red laser light at room temperature. Remarkable polarization anisotropy in the modulation is observed. lambda-dependence of the polarization anisotropy is analyzed by a simple model based on the optical anisotropy observed in absorption spectra. (C) 2002 Elsevier Science B.V. All rights reserved.

Reflectivity and ellipsometry methods were applied to study optical properties of type-II ZnSe/BeTe superlattices. Natural in-plane optical anisotropy of the refractive and absorption indices has been found in the spectral range of direct excitonic transitions. The observed effects are interpreted in a model of optical anisotropy of heterostructures with no-common atom at the interfaces., This article is from ADA408025 Nanostructures: Physics and Technology International Symposium (9th), St. Petersburg, Russia, June 18-22, 2001 Proceedings

Rubbing-induced molecular alignment and its relaxation in polystyrene (PS) thin films are studied with optical birefringence. A novel relaxation of the alignment is observed that is distinctly different from the known relaxation processes of PS. First, it is not the Kohlrausch-Williams-Watts type but instead is characterized by two single exponentials plus a temperature-dependent constant. At temperatures several degrees or more below the glass-transition temperature (T-g), the relaxation time falls between that of the a and beta relaxations. Second, the decay time constants are the same within 40\% for PS with weight-average molecular weights (M-w's) of 13,700-550,000 Da at temperatures well below the sample T-g `s, indicating that the molecular relaxations involved are mostly local within the entanglement distance. Nonetheless, the temperature at which the rubbing-induced molecular alignment disappears (TO) exhibits a strong M-w dependence and closely approximates the T-g of the sample. Furthermore, To depends notably on the thickness of the polymer in much the same way as previously found for the T-g of supported PS films. This suggests that the a process becomes dominant near T-g. Preliminary spectroscopic studies in the mid-infrared range show a significant degree of bending of the phenyl ring toward the sample surface, with the C-C bond connecting the phenyl ring and the main chain tends to lie along the rubbing direction, which indicates that the relaxation is connected with the reorientation of this C-C bond. We exclude the observed relaxation, as predominantly a near-surface one, because detailed studies on the effects of rubbing conditions on the degree of molecular alignment indicate that the alignment is not local to the polymer-air surface. (C) 2001 John Wiley & Sons, Inc.

Rubbing-induced molecular alignment and its relaxation in polystyrene (PS) thin films are studied with optical birefringence. A novel relaxation of the alignment is observed that is distinctly different from the known relaxation processes of PS. First, it is not the Kohlrausch-Williams-Watts type but instead is characterized by two single exponentials plus a temperature-dependent constant. At temperatures several degrees or more below the glass-transition temperature (T-g), the relaxation time falls between that of the a and beta relaxations. Second, the decay time constants are the same within 40\% for PS with weight-average molecular weights (M-w's) of 13,700-550,000 Da at temperatures well below the sample T-g `s, indicating that the molecular relaxations involved are mostly local within the entanglement distance. Nonetheless, the temperature at which the rubbing-induced molecular alignment disappears (TO) exhibits a strong M-w dependence and closely approximates the T-g of the sample. Furthermore, To depends notably on the thickness of the polymer in much the same way as previously found for the T-g of supported PS films. This suggests that the a process becomes dominant near T-g. Preliminary spectroscopic studies in the mid-infrared range show a significant degree of bending of the phenyl ring toward the sample surface, with the C-C bond connecting the phenyl ring and the main chain tends to lie along the rubbing direction, which indicates that the relaxation is connected with the reorientation of this C-C bond. We exclude the observed relaxation, as predominantly a near-surface one, because detailed studies on the effects of rubbing conditions on the degree of molecular alignment indicate that the alignment is not local to the polymer-air surface. (C) 2001 John Wiley & Sons, Inc.

The results of generalized anisotropic ellipsometry on a biaxial organic single crystal, namely, potassium acid phthalate, are discussed and analyzed to obtain the optical functions of the crystal along the different crystal directions. The dispersion of the real refractive indices n(x), n(y), and n(z) in the spectral range from 300 to 1400 nm, as well as the values of the extinction coefficient k(x,y) at the absorption edge are determined and modeled. (C) 2001 American Institute of Physics

Polarized infrared absorbance spectrum of an optically anisotropic crystal was formulated for the crystallographic analysis of the hydrous component in the crystal under Fourier transform polarized infrared absorbance spectroscopy (pol-mFTIR). The adequacy of the formulation was confirmed by comparison of calculated interference fringes with those identical to the observed one in polarized absorbance spectra of an optically anisotropic crystal....

Polarized infrared absorbance spectrum of an optically anisotropic crystal was formulated for the crystallographic analysis of the hydrous component in the crystal under Fourier transform polarized infrared absorbance spectroscopy (pol-mFTIR). The adequacy of the formulation was confirmed by comparison of calculated interference fringes with those identical to the observed one in polarized absorbance spectra of an optically anisotropic crystal....

Mismatched epitaxial layers of In(x)Ga(1-x)As and In(y)Al(1-y)As were grown on (001) InP by molecular beam epitaxy. The layers were characterized by a technique we developed known as variable azimuthal-angle ellipsometry. It reveals large optical anisotropy for many strained layers. We attribute the anisotropy to strain-induced surface roughening during growth. Samples were also characterized by high-resolution x-ray diffraction (HRXRD) to assess layer quality as well as composition and strain. HRXRD measurements reveal orthorhombic distortion of partially relaxed layers of InGaAs and InAlAs in tension or compression, with preferential strain relief in the 110 direction. We show that HRXRD epilayer peak width and interference fringes are sensitive, non-destructive criteria to judge the structural quality of strained heterostructures. For layers ranging from 300 to 10,000 A, with lattice mismatch of +/- 1% or less, the crystalline quality consistently remains high to thicknesses up to 3-9 times the Matthews-Blakeslee critical layer thickness. We investigated the thermal stability of these layers, using HRXRD to measure structural changes caused by high-temperature anneals. We also compared the electron mobility of modulation- doped heterostructures before and after annealing. Both techniques demonstrate that our high-quality strained layers are stable to temperatures of at least 800-859 deg C. We explain this result by the limited sources available for the nucleation of misfit dislocations. The findings are applied to the design and growth of high-performance pseudomorphic InAlAs /InGaAs /InP heterostructure field-effect transistors with layers exceeding the Matthews-Blakeslee limit., Doctoral thesis.

Tato disertační práce se zabývá tématikou analýzy strukturálních změn ve svalové tkáni a metodikou optického měření. I přesto, že existuje nezanedbatelné množství metod pro detekci konkrétních změn ve svalovině, především pak v konzumním mase, drtivá většina z nich se zaměřuje na jeden konkrétní proces a vyžaduje komplikované postupy a drahé přístroje. Předmětem prezentovaného výzkumu není tedy nalézt metody přesnější a specifičtější, než jsou ty již exitující, ale raději zvolit alternativní přístup k problematice. Součástí je pak i snaha najít možnosti jak obejít technologické nároky moderních postupů a přitom se přiblížit co nejvíce jejich informačnímu přínosu. Za tímto účelem je potřeba mít dostatečné teoretické znalosti a experimentální zkušenosti především v oboru fyziky, optiky a postupů měření, ale také široké povědomí o problematice biologických tkání a procesů v nich probíhajících. Na základě získaných informací a pochopení pochodů ve svalové tkáni jsou navrhnuty a testovány tři rozdílné přístupy. Vytvořené metody pracují s fotony v transmisním i reflexním uspořádání. Pomocí pozorování změn absorpce, rozptylu a polarizace světla po interakci se vzorkem svalové tkáně jsou posouzeny jeho další optické vlastnosti především index lomu a optická anizotropie. Identifikace změn optických vlastností vzorků za různých podmínek umožňuje společně se simulací Monte Carlo posoudit rozdíly mezi vzorky čerstvými, starými, sušenými a jednou či dvakrát zmraženými a rozmraženými., In this dissertation the topic of structural change analysis of muscle tissue and the methodical approach to this measurement is explored. Even though a considerable number of detection methods for the evaluation of specific changes in muscles exist, especially in the meat intended for consumption, the vast majority focuses only on a single process within the tissue and requires complicated approach and expensive instruments. The topic of this work is therefore not finding more precise and specific means of analysis, than the already existing ones, but rather to select an alternative approach to the given problematic. Part of the explored approach is also the endeavor to find a way to bypass the technological requirements while staying as close to the informational value of the high end methods as possible. To this end an informational base of theoretical knowledge and the experience in experimental approaches in the field of physics, optics and biological tissues and processes is required. The three main approaches described in this work are based on the acquired information throughout the research of the topic and understanding of the basic workings of muscle tissue. The methods created for this thesis make use of photons in the transmission and reflection measurement setup. By observing the changes in absorption, dispersion and polarization of the light after the interaction with muscle tissue sample the other optical parameters are evaluated, including the refractive index and optical anisotropy. The identification of changes in optical parameters together with the Monte Carlo simulation allows for distinction between fresh, aged, dried, frozen and thawed, and refrozen and thawed samples.

Tato disertační práce se zabývá tématikou analýzy strukturálních změn ve svalové tkáni a metodikou optického měření. I přesto, že existuje nezanedbatelné množství metod pro detekci konkrétních změn ve svalovině, především pak v konzumním mase, drtivá většina z nich se zaměřuje na jeden konkrétní proces a vyžaduje komplikované postupy a drahé přístroje. Předmětem prezentovaného výzkumu není tedy nalézt metody přesnější a specifičtější, než jsou ty již exitující, ale raději zvolit alternativní přístup k problematice. Součástí je pak i snaha najít možnosti jak obejít technologické nároky moderních postupů a přitom se přiblížit co nejvíce jejich informačnímu přínosu. Za tímto účelem je potřeba mít dostatečné teoretické znalosti a experimentální zkušenosti především v oboru fyziky, optiky a postupů měření, ale také široké povědomí o problematice biologických tkání a procesů v nich probíhajících. Na základě získaných informací a pochopení pochodů ve svalové tkáni jsou navrhnuty a testovány tři rozdílné přístupy. Vytvořené metody pracují s fotony v transmisním i reflexním uspořádání. Pomocí pozorování změn absorpce, rozptylu a polarizace světla po interakci se vzorkem svalové tkáně jsou posouzeny jeho další optické vlastnosti především index lomu a optická anizotropie. Identifikace změn optických vlastností vzorků za různých podmínek umožňuje společně se simulací Monte Carlo posoudit rozdíly mezi vzorky čerstvými, starými, sušenými a jednou či dvakrát zmraženými a rozmraženými., In this dissertation the topic of structural change analysis of muscle tissue and the methodical approach to this measurement is explored. Even though a considerable number of detection methods for the evaluation of specific changes in muscles exist, especially in the meat intended for consumption, the vast majority focuses only on a single process within the tissue and requires complicated approach and expensive instruments. The topic of this work is therefore not finding more precise and specific means of analysis, than the already existing ones, but rather to select an alternative approach to the given problematic. Part of the explored approach is also the endeavor to find a way to bypass the technological requirements while staying as close to the informational value of the high end methods as possible. To this end an informational base of theoretical knowledge and the experience in experimental approaches in the field of physics, optics and biological tissues and processes is required. The three main approaches described in this work are based on the acquired information throughout the research of the topic and understanding of the basic workings of muscle tissue. The methods created for this thesis make use of photons in the transmission and reflection measurement setup. By observing the changes in absorption, dispersion and polarization of the light after the interaction with muscle tissue sample the other optical parameters are evaluated, including the refractive index and optical anisotropy. The identification of changes in optical parameters together with the Monte Carlo simulation allows for distinction between fresh, aged, dried, frozen and thawed, and refrozen and thawed samples.

Tato disertační práce se zabývá tématikou analýzy strukturálních změn ve svalové tkáni a metodikou optického měření. I přesto, že existuje nezanedbatelné množství metod pro detekci konkrétních změn ve svalovině, především pak v konzumním mase, drtivá většina z nich se zaměřuje na jeden konkrétní proces a vyžaduje komplikované postupy a drahé přístroje. Předmětem prezentovaného výzkumu není tedy nalézt metody přesnější a specifičtější, než jsou ty již exitující, ale raději zvolit alternativní přístup k problematice. Součástí je pak i snaha najít možnosti jak obejít technologické nároky moderních postupů a přitom se přiblížit co nejvíce jejich informačnímu přínosu. Za tímto účelem je potřeba mít dostatečné teoretické znalosti a experimentální zkušenosti především v oboru fyziky, optiky a postupů měření, ale také široké povědomí o problematice biologických tkání a procesů v nich probíhajících. Na základě získaných informací a pochopení pochodů ve svalové tkáni jsou navrhnuty a testovány tři rozdílné přístupy. Vytvořené metody pracují s fotony v transmisním i reflexním uspořádání. Pomocí pozorování změn absorpce, rozptylu a polarizace světla po interakci se vzorkem svalové tkáně jsou posouzeny jeho další optické vlastnosti především index lomu a optická anizotropie. Identifikace změn optických vlastností vzorků za různých podmínek umožňuje společně se simulací Monte Carlo posoudit rozdíly mezi vzorky čerstvými, starými, sušenými a jednou či dvakrát zmraženými a rozmraženými., In this dissertation the topic of structural change analysis of muscle tissue and the methodical approach to this measurement is explored. Even though a considerable number of detection methods for the evaluation of specific changes in muscles exist, especially in the meat intended for consumption, the vast majority focuses only on a single process within the tissue and requires complicated approach and expensive instruments. The topic of this work is therefore not finding more precise and specific means of analysis, than the already existing ones, but rather to select an alternative approach to the given problematic. Part of the explored approach is also the endeavor to find a way to bypass the technological requirements while staying as close to the informational value of the high end methods as possible. To this end an informational base of theoretical knowledge and the experience in experimental approaches in the field of physics, optics and biological tissues and processes is required. The three main approaches described in this work are based on the acquired information throughout the research of the topic and understanding of the basic workings of muscle tissue. The methods created for this thesis make use of photons in the transmission and reflection measurement setup. By observing the changes in absorption, dispersion and polarization of the light after the interaction with muscle tissue sample the other optical parameters are evaluated, including the refractive index and optical anisotropy. The identification of changes in optical parameters together with the Monte Carlo simulation allows for distinction between fresh, aged, dried, frozen and thawed, and refrozen and thawed samples.

Thesis (B.S.)--University of Rochester. Dept. of Physics and Astronomy, 1999., The Lorentz-Penin planar oscillator model for the anisotropy of optical properties of planar molecules is generalized to include near-degenerate transitions. The model displays a strong correlation with experimental data for the optical anisotropy of the FennaMatthews-Olson trimer of the green sulfur photosynthetic bacterium Chlorobium tepidum and for the C-phycocyanin trimer of cyanobacteria.

In recent years composite materials find wide application in various fields of engineering, because they have a number of advantages over other structural materials. A variety of composites' physical and mechanical properties (especially anisotropy) requires an improvement of existing calculation methods and creation of new ones for structural elements made of these materials. This is an important task which will contribute to their wider use. In this paper some famous criteria of anisotropic materials are examined, and their advantages and disadvan-tages are discussed. The authors of the paper suggest new variants of strength criteria for anisotropic materials. These new criteria are based on new mechanical characteristics which are more convenient for experimental obtaining. Also new criteria use separate form of writing for each quadrant of the stress plain. © Published under licence by IOP Publishing Ltd.

Thesis (B.S.)--University of Rochester. Dept. of Physics and Astronomy, 1999., The Lorentz-Penin planar oscillator model for the anisotropy of optical properties of planar molecules is generalized to include near-degenerate transitions. The model displays a strong correlation with experimental data for the optical anisotropy of the FennaMatthews-Olson trimer of the green sulfur photosynthetic bacterium Chlorobium tepidum and for the C-phycocyanin trimer of cyanobacteria.

Tato disertační práce se zabývá tématikou analýzy strukturálních změn ve svalové tkáni a metodikou optického měření. I přesto, že existuje nezanedbatelné množství metod pro detekci konkrétních změn ve svalovině, především pak v konzumním mase, drtivá většina z nich se zaměřuje na jeden konkrétní proces a vyžaduje komplikované postupy a drahé přístroje. Předmětem prezentovaného výzkumu není tedy nalézt metody přesnější a specifičtější, než jsou ty již exitující, ale raději zvolit alternativní přístup k problematice. Součástí je pak i snaha najít možnosti jak obejít technologické nároky moderních postupů a přitom se přiblížit co nejvíce jejich informačnímu přínosu. Za tímto účelem je potřeba mít dostatečné teoretické znalosti a experimentální zkušenosti především v oboru fyziky, optiky a postupů měření, ale také široké povědomí o problematice biologických tkání a procesů v nich probíhajících. Na základě získaných informací a pochopení pochodů ve svalové tkáni jsou navrhnuty a testovány tři rozdílné přístupy. Vytvořené metody pracují s fotony v transmisním i reflexním uspořádání. Pomocí pozorování změn absorpce, rozptylu a polarizace světla po interakci se vzorkem svalové tkáně jsou posouzeny jeho další optické vlastnosti především index lomu a optická anizotropie. Identifikace změn optických vlastností vzorků za různých podmínek umožňuje společně se simulací Monte Carlo posoudit rozdíly mezi vzorky čerstvými, starými, sušenými a jednou či dvakrát zmraženými a rozmraženými., In this dissertation the topic of structural change analysis of muscle tissue and the methodical approach to this measurement is explored. Even though a considerable number of detection methods for the evaluation of specific changes in muscles exist, especially in the meat intended for consumption, the vast majority focuses only on a single process within the tissue and requires complicated approach and expensive instruments. The topic of this work is therefore not finding more precise and specific means of analysis, than the already existing ones, but rather to select an alternative approach to the given problematic. Part of the explored approach is also the endeavor to find a way to bypass the technological requirements while staying as close to the informational value of the high end methods as possible. To this end an informational base of theoretical knowledge and the experience in experimental approaches in the field of physics, optics and biological tissues and processes is required. The three main approaches described in this work are based on the acquired information throughout the research of the topic and understanding of the basic workings of muscle tissue. The methods created for this thesis make use of photons in the transmission and reflection measurement setup. By observing the changes in absorption, dispersion and polarization of the light after the interaction with muscle tissue sample the other optical parameters are evaluated, including the refractive index and optical anisotropy. The identification of changes in optical parameters together with the Monte Carlo simulation allows for distinction between fresh, aged, dried, frozen and thawed, and refrozen and thawed samples.

Tato disertační práce se zabývá tématikou analýzy strukturálních změn ve svalové tkáni a metodikou optického měření. I přesto, že existuje nezanedbatelné množství metod pro detekci konkrétních změn ve svalovině, především pak v konzumním mase, drtivá většina z nich se zaměřuje na jeden konkrétní proces a vyžaduje komplikované postupy a drahé přístroje. Předmětem prezentovaného výzkumu není tedy nalézt metody přesnější a specifičtější, než jsou ty již exitující, ale raději zvolit alternativní přístup k problematice. Součástí je pak i snaha najít možnosti jak obejít technologické nároky moderních postupů a přitom se přiblížit co nejvíce jejich informačnímu přínosu. Za tímto účelem je potřeba mít dostatečné teoretické znalosti a experimentální zkušenosti především v oboru fyziky, optiky a postupů měření, ale také široké povědomí o problematice biologických tkání a procesů v nich probíhajících. Na základě získaných informací a pochopení pochodů ve svalové tkáni jsou navrhnuty a testovány tři rozdílné přístupy. Vytvořené metody pracují s fotony v transmisním i reflexním uspořádání. Pomocí pozorování změn absorpce, rozptylu a polarizace světla po interakci se vzorkem svalové tkáně jsou posouzeny jeho další optické vlastnosti především index lomu a optická anizotropie. Identifikace změn optických vlastností vzorků za různých podmínek umožňuje společně se simulací Monte Carlo posoudit rozdíly mezi vzorky čerstvými, starými, sušenými a jednou či dvakrát zmraženými a rozmraženými., In this dissertation the topic of structural change analysis of muscle tissue and the methodical approach to this measurement is explored. Even though a considerable number of detection methods for the evaluation of specific changes in muscles exist, especially in the meat intended for consumption, the vast majority focuses only on a single process within the tissue and requires complicated approach and expensive instruments. The topic of this work is therefore not finding more precise and specific means of analysis, than the already existing ones, but rather to select an alternative approach to the given problematic. Part of the explored approach is also the endeavor to find a way to bypass the technological requirements while staying as close to the informational value of the high end methods as possible. To this end an informational base of theoretical knowledge and the experience in experimental approaches in the field of physics, optics and biological tissues and processes is required. The three main approaches described in this work are based on the acquired information throughout the research of the topic and understanding of the basic workings of muscle tissue. The methods created for this thesis make use of photons in the transmission and reflection measurement setup. By observing the changes in absorption, dispersion and polarization of the light after the interaction with muscle tissue sample the other optical parameters are evaluated, including the refractive index and optical anisotropy. The identification of changes in optical parameters together with the Monte Carlo simulation allows for distinction between fresh, aged, dried, frozen and thawed, and refrozen and thawed samples.

Tato disertační práce se zabývá tématikou analýzy strukturálních změn ve svalové tkáni a metodikou optického měření. I přesto, že existuje nezanedbatelné množství metod pro detekci konkrétních změn ve svalovině, především pak v konzumním mase, drtivá většina z nich se zaměřuje na jeden konkrétní proces a vyžaduje komplikované postupy a drahé přístroje. Předmětem prezentovaného výzkumu není tedy nalézt metody přesnější a specifičtější, než jsou ty již exitující, ale raději zvolit alternativní přístup k problematice. Součástí je pak i snaha najít možnosti jak obejít technologické nároky moderních postupů a přitom se přiblížit co nejvíce jejich informačnímu přínosu. Za tímto účelem je potřeba mít dostatečné teoretické znalosti a experimentální zkušenosti především v oboru fyziky, optiky a postupů měření, ale také široké povědomí o problematice biologických tkání a procesů v nich probíhajících. Na základě získaných informací a pochopení pochodů ve svalové tkáni jsou navrhnuty a testovány tři rozdílné přístupy. Vytvořené metody pracují s fotony v transmisním i reflexním uspořádání. Pomocí pozorování změn absorpce, rozptylu a polarizace světla po interakci se vzorkem svalové tkáně jsou posouzeny jeho další optické vlastnosti především index lomu a optická anizotropie. Identifikace změn optických vlastností vzorků za různých podmínek umožňuje společně se simulací Monte Carlo posoudit rozdíly mezi vzorky čerstvými, starými, sušenými a jednou či dvakrát zmraženými a rozmraženými., In this dissertation the topic of structural change analysis of muscle tissue and the methodical approach to this measurement is explored. Even though a considerable number of detection methods for the evaluation of specific changes in muscles exist, especially in the meat intended for consumption, the vast majority focuses only on a single process within the tissue and requires complicated approach and expensive instruments. The topic of this work is therefore not finding more precise and specific means of analysis, than the already existing ones, but rather to select an alternative approach to the given problematic. Part of the explored approach is also the endeavor to find a way to bypass the technological requirements while staying as close to the informational value of the high end methods as possible. To this end an informational base of theoretical knowledge and the experience in experimental approaches in the field of physics, optics and biological tissues and processes is required. The three main approaches described in this work are based on the acquired information throughout the research of the topic and understanding of the basic workings of muscle tissue. The methods created for this thesis make use of photons in the transmission and reflection measurement setup. By observing the changes in absorption, dispersion and polarization of the light after the interaction with muscle tissue sample the other optical parameters are evaluated, including the refractive index and optical anisotropy. The identification of changes in optical parameters together with the Monte Carlo simulation allows for distinction between fresh, aged, dried, frozen and thawed, and refrozen and thawed samples.