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1
Kudenov, Michael W. "Infrared Stokes Polarimetry and Spectropolarimetry." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/193729.
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In this work, three methods of measuring the polarization state of light in the thermal infrared (3-12 microns) are modeled, simulated, calibrated and experimentally verified in the laboratory. The first utilizes the method of channeled spectropolarimetry (CP) to encode the Stokes polarization parameters onto the optical power spectrum. This channeled spectral technique is implemented with the use of two Yttrium Vanadate (YVO4) crystal retarders. A basic mathematical model for the system is presented, showing that all the Stokes parameters are directly present in the interferogram. Theoretical results are compared with real data from the system, an improved model is provided to simulate the effects of absorption within the crystal, and a modified calibration technique is introduced to account for this absorption. Lastly, effects due to interferometer instabilities on the reconstructions, including nonuniform sampling and interferogram translations, are investigated and techniques are employed to mitigate them.Second is the method of prismatic imaging polarimetry (PIP), which can be envisioned as the monochromatic application of channeled spectropolarimetry. Unlike CP, PIP encodes the 2-dimensional Stokes parameters in a scene onto spatial carrier frequencies. However, the calibration techniques derived in the infrared for CP are extremely similar to that of the PIP. Consequently, the PIP technique is implemented with a set of four YVO4 crystal prisms. A mathematical model for the polarimeter is presented in which diattenuation due to Fresnel effects and dichroism in the crystal are included. An improved polarimetric calibration technique is introduced to remove the diattenuation effects, along with the relative radiometric calibration required for the BPIP operating with a thermal background and large detector offsets. Data demonstrating emission polarization are presented from various blackbodies, which are compared to data from our Fourier transform infrared spectropolarimeter. Additionally, limitations in the PIP technique with regards to the spectral bandwidth and F/# of the imaging system are analyzed. A model able to predict the carrier frequency's fringe visibility is produced and experimentally verified, further reinforcing the PIP's limitations.The last technique is significantly different from CP or PIP and involves the simulation and calibration of a thermal infrared division of amplitude imaging Stokes polarimeter. For the first time, application of microbolometer focal plane array (FPA) technology to polarimetry is demonstrated. The sensor utilizes a wire-grid beamsplitter with imaging systems positioned at each output to analyze two orthogonal linear polarization states simultaneously. Combined with a form birefringent wave plate, the system is capable of snapshot imaging polarimetry in any one Stokes vector (S1, S2 or S3). Radiometric and polarimetric calibration procedures for the instrument are provided and the reduction matrices from the calibration are compared to rigorous coupled wave analysis (RCWA) and raytracing simulations. The design and optimization of the sensor's wire-grid beam splitter and wave plate are presented, along with their corresponding prescriptions. Polarimetric calibration error due to the spectrally broadband nature of the instrument is also overviewed. Image registration techniques for the sensor are discussed and data from the instrument are presented, demonstrating a microbolometer's ability to measure the small intensity variations corresponding to polarized emission in natural environments.
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Yong, Siow Yin. "Radar polarimetry." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Dec%5FYong.pdf.
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Bernasconi, Pietro Nicola. "Stokes vector-polarimetry : observation and analysis of solar magnetic fields /." [S.l.] : [s.n.], 1997. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=12227.
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Narayan, Chaya. "Study of Optically Active Biological Fluids Using Polarimetric Data Analysis." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1314038487.
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Adams, Ian. "SIMULATION AND STUDY OF THE STOKES VECTOR IN A PRECIPITATING ATMOSPHERE." Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3479.
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Precipitation is a dominating quantity in microwave radiometry. The large emission and scattering signals of rain and ice, respectively, introduce large contributions to the measured brightness temperature. While this allows for accurate sensing of precipitation, it also results in degraded performance when retrieving other geophysical parameters, such as near-surface ocean winds. In particular, the retrieval of wind direction requires precise knowledge of polarization, and nonspherical particles can result in a change in the polarization of incident radiation. The aim of this dissertation is to investigate the polarizing effects of precipitation in the atmosphere, including the existence of a precipitation signal in the third Stokes parameter, and compare these effects with the current sensitivities of passive wind vector retrieval algorithms. Realistic simulated precipitation profiles give hydrometeor water contents which are input into a vector radiative transfer model. Brightness temperatures are produced within the model using a reverse Monte Carlo method. Results are produced at three frequencies of interest to microwave polarimetry, 10.7 GHz, 18.7 GHz, and 37.0 GHz, for the first 3 components of the Stokes vector.Ph.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering PhD
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Mu, Tingkui, Shaun Pacheco, Zeyu Chen, Chunmin Zhang, and Rongguang Liang. "Snapshot linear-Stokes imaging spectropolarimeter using division-of-focal-plane polarimetry and integral field spectroscopy." NATURE PUBLISHING GROUP, 2017. http://hdl.handle.net/10150/622866.
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In this paper, the design and experimental demonstration of a snapshot linear-Stokes imaging spectropolarimeter (SLSIS) is presented. The SLSIS, which is based on division-of-focal-plane polarimetry with four parallel linear polarization channels and integral field spectroscopy with numerous slit dispersive paths, has no moving parts and provides video-rate Stokes-vector hyperspectral datacubes. It does not need any scanning in the spectral, spatial or polarization dimension and offers significant advantages of rapid reconstruction without heavy computation during post-processing. The principle and the experimental setup of the SLSIS are described in detail. The image registration, Stokes spectral reconstruction and calibration procedures are included, and the system is validated using measurements of tungsten light and a static scene. The SLSIS's snapshot ability to resolve polarization spectral signatures is demonstrated using measurements of a dynamic scene.
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Narayan, Chaya. "Polarimetric Stokes Imaging for the Detection of Tumor Margins and Segmentation." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1386785379.
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Bradley, Christine Lavella, and Christine Lavella Bradley. "SpectroPolarimetric Imaging Observations." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/624499.
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The capability to map anthropogenic aerosol quantities and properties over land can provide significant insights for climate and environmental studies on global and regional scales. One of the primary challenges in aerosol information monitoring is separating two signals measured by downward-viewing airborne or spaceborne instruments: the light scattered from the aerosols and light reflected from the Earth's surface. In order to study the aerosols independently, the surface signal needs to be subtracted out from the measurements. Some observational modalities, such as multispectral and multiangle, do not provide enough information to uniquely define the Earth's directional reflectance properties for this task due to the high magnitude and inhomogeneity of albedo for land surface types. Polarization, however, can provide additional information to define surface reflection. To improve upon current measurement capabilities of aerosols over urban areas, Jet Propulsion Laboratory developed the Multiangle SpectroPolarimetric Imager (MSPI) that can accurately measure the Degree of Linear Polarization to 0.5%. In particular, data acquired by the ground-based prototype, GroundMSPI, is used for directional reflectance studies of outdoor surfaces in this dissertation. This work expands upon an existing model, the microfacet model, to characterize the polarized bidirectional reflectance distribution function (pBRDF) of surfaces and validate an assumption, the Spectral Invariance Hypothesis, on the surface pBRDF that is used in aerosol retrieval algorithms.
The microfacet model is commonly used to represent the pBRDF of Earth's surface types, such as ocean and land. It represents a roughened surface comprised of randomly oriented facets that specularly reflect incoming light into the upward hemisphere. The analytic form of the pBRDF for this model assumes only a single reflection of light from the microfaceted surface. If the incoming illumination is unpolarized, as it is with natural light from the Sun, the reflected light is linearly polarized perpendicular to the plane that contains the illumination and view directions, the scattering plane. However, previous work has shown that manmade objects, such as asphalt and brick, show a polarization signature that differs from the single reflection microfacet model. Using the polarization ray-tracing (PRT) program POLARIS-M, a numerical calculation for the pBRDF is made for a roughened surface to account for multiple reflections that light can experience between microfacets. Results from this numerical PRT method shows rays that experience two or more reflections with the microfacet surface can be polarized at an orientation that differs from the analytical single reflection microfacet model. This PRT method is compared against GroundMSPI data of manmade surfaces.
An assumption made regarding the pBRDF for this microfacet model is verified with GroundMSPI data of urban areas. This is known as the Spectral Invariance Hypothesis and asserts that the magnitude and shape of the polarized bidirectional reflectance factor (pBRF) is the same for all wavelengths. This simplifies the microfacet model by assuming some surface parameters such as the index of refraction are spectrally neutral. GroundMSPI acquires the pBRF for five prominent region types, asphalt, brick, cement, dirt, and grass, for day-long measurements on clear sky conditions. Over the course of each day, changing solar position in the sky provides a large range of scattering angles for this study. The pBRF is measured for the three polarimetric wavelengths of GroundMSPI, 470, 660, and 865nm, and the best fit slope of the spectral correlation is reported. This investigation shows agreement to the Spectral Invariance Hypothesis within 10% for all region types excluding grass. Grass measurements show a large mean deviation of 31.1%. This motivated an angle of linear polarization (AoLP) analysis of cotton crops to isolate single reflection cases, or specular reflections, from multiple scattering cases of light in vegetation. Results from this AoLP method show that specular reflections off the top surface of leaves follow the Spectral Invariance Hypothesis.
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Petermann, Jeff C. "Design of a Fully Automated Polarimetric Imaging System for Remote Characterization of Space Materials." University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1329101390.
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Gendre, Luc. "Conception et réalisation d'un polarimètre de Stokes haute cadence à division temporelle utilisant un unique modulateur à cristaux liquides ferroélectriques pour moduler la polarisation." Phd thesis, Université de Haute Alsace - Mulhouse, 2011. http://tel.archives-ouvertes.fr/tel-00713656.
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L'imagerie de polarisation apporte des informations complémentaires à l'imagerie conventionnelle. L'oeil humain n'étant cependant pas sensible à la polarisation de la lumière, l'utilisation d'équipements spécifiques est indispensable. Depuis le XIXème siècle, des scientifiques étudient la polarisation de la lumière: d'abord avec de simples lames polarisantes, puis depuis une vingtaine d'années à l'aide de modulateurs à cristaux liquides (CL). Ces derniers présentent un avantage considérable par rapport aux lames polarisantes: ils permettent des vitesses de modulation de la polarisation de la lumière qui ne peuvent être atteintes avec des lames orientées mécaniquement. Les CL nématiques alignés parallèlement et les CL nématiques en hélice sont les plus répandus aujourd'hui, que ce soit dans des équipements grand public tels que les écrans d'ordinateur, ou dans des équipements professionnels. Ils fonctionnent à des fréquences maximales de l'ordre de 50Hz. La vitesse de fonctionnement de ces CL peut toutefois encore être dépassée en utilisant des CL ferroélectriques, pouvant atteindre le kiloHertz. Ces éléments sont rapportés dans la littérature comme des éléments bistables, donc ne permettant pas de moduler la polarisation incidente de manière accordable, contrairement aux CL nématiques. En d'autres termes, un seul modulateur à CL ferroélectriques ne permet a priori pas d'analyser la totalité de la polarisation. Seulement une fraction de la polarisation linéaire du faisceau incident peut être identifiée.Le présent travail vise à montrer qu'a posteriori des CL ferroélectriques convenablement commandés peuvent être utilisés de manière accordable pour analyser la totalité de la polarisation. Partant d'un modulateur à CL ferroélectriques conventionnel, il est montré dans un premier temps que l'on peut analyser la totalité de la polarisation linéaire dès lors que la commande électrique est adaptée. Puis dans un deuxième temps, en exploitant la dépendance en longueur d'onde du comportement du modulateur, nous démontrons que cet élément optique peut être utilisé pour analyser la totalité de la polarisation du faisceau incident, c'est-à-dire la composante linéaire aussi bien que circulaire. Un polarimètre à division temporelle est développé pour prouver la faisabilité d'un polarimètre n'utilisant qu'un seul et unique modulateur à CL ferroélectriques pour tout élément polarisant. Un défaut a également été mis en évidence dans la restitution de l'information de polarisation avec un polarimètre à division temporelle lors de l'observation d'objets en mouvement. Avec un tel système, l'acquisition des différentes images d'intensités nécessaires à l'estimation de l'information de polarisation se fait séquentiellement. Par conséquent, le mouvement d'un objet dans la scène pendant la phase d'acquisition se répercute sur la séquence d'images d'intensités, ce qui produit des artéfacts lors de l'estimation de la polarisation. Des solutions à ce problème sont proposées.
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Jones, Julia Craven. "Infrared Hyperspectral Imaging Stokes Polarimeter." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/145409.
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This work presents the design, development, and testing of a field portable imaging spectropolarimeter that operates over the short-wavelength and middle-wavelength portion of the infrared spectrum. The sensor includes a pair of sapphire Wollaston prisms and several high order retarders to produce the first infrared implementation of an imaging Fourier transform spectropolarimeter, providing for the measurement of the complete spectropolarimetric datacube over the passband. The Wollaston prisms serve as a birefringent interferometer with reduced sensitivity to vibration when compared to an unequal path interferometer, such as a Michelson. Polarimetric data are acquired through the use of channeled spectropolarimetry to modulate the spectrum with the Stokes parameter information. The collected interferogram is Fourier filtered and reconstructed to recover the spatially and spectrally varying Stokes vector data across the image.The intent of this dissertation is to provide the reader with a detailed understanding of the steps involved in the development of this infrared hyperspectral imaging polarimeter (IHIP) instrument. First, Chapter 1 provides an overview of the fundamental concepts relevant to this research. These include imaging spectrometers, polarimeters, and spectropolarimeters. A detailed discussion of channeled spectropolarimetry, including a historical study of previous implementations, is also presented. Next a few of the design alternatives that are possible for this work are outlined and discussed in Chapter 2. The configuration that was selected for the IHIP is then presented in detail, including the optical layout, design, and operation. Chapter 3 then presents an artifact reduction technique (ART) that was developed to improve the IHIP's spectropolarimetric reconstructions by reducing errors associated with non-band-limited spectral features. ART is experimentally verified in the infrared using a commercial Fourier transform spectrometer in combination with Yttrium Vanadate as well as Cadmium Sulfide retarders.The remainder of this dissertation then details the testing and analysis of the IHIP instrument. Implementation of ART with the IHIP as well as the employed calibration techniques are described in Chapter 4. Complete calibration of the IHIP includes three distinct processes to provide radiometric, spectral, and polarimetric calibration. With the instrument assembled and calibrated, results and error analyses are presented in Chapter 5. Spectropolarimetric results are obtained in the laboratory as well as outdoors to test the IHIP's real world functionality. The performance of the instrument is also assessed, including experimental measurement of signal-to-noise ratio (SNR), and an analysis of the potential sources of systematic error (such as retarder misalignment and finite polarizer extinction ratio). Chapter 6 presents the design and experimental results for a variable Wollaston prism that can be added to the IHIP to vary the fringe contrast across the field of view. Finally, Chapter 7 includes brief closing remarks summarizing this work and a few observations which may be useful for future infrared imaging Fourier transform channeled spectropolarimeter instruments.
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Murali, Sukumar. "Analysis of an Interferometric Stokes Imaging Polarimeter." Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/194148.
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Estimation of Stokes vector components from an interferometric fringe encoded image is a novel way of measuring the State Of Polarization (SOP) distribution across a scene. Imaging polarimeters employing interferometric techniques encode SOP information in a single image in the form of fringes. The lack of moving parts and the use of a single image eliminates the problems of conventional polarimetry - vibration, spurious signal generation due to artifacts, beam wander and the need for registration routines. However, interferometric polarimeters are limited by narrow band pass operation and short exposure time operations which decrease the Signal to Noise Ratio (SNR) in the detected image.A simulation environment for designing an Interferometric Stokes Imaging polarimeter (ISIP) and a detector with noise effects is created and presented. A user is capable of imaging an object with defined SOP through an ISIP on to a detector producing a digitized image output. The simulation also includes band pass imaging capabilities, control of detector noise, and object brightness levels.The Stokes images are estimated from a fringe encoded image of a scene by means of a reconstructor algorithm. A spatial domain methodology involving the idea of a unit cell and slide approach is applied to the reconstructor model developed using Mueller calculus. The validation of this methodology and effectiveness compared to a discrete approach is demonstrated with suitable examples. The pixel size required to sample the fringes and the minimum unit cell size required for reconstruction are investigated using condition numbers. The importance of the PSF of fore-optics (telescope) used in imaging the object is investigated and analyzed using a point source imaging example and a Nyquist criteria is presented.Reconstruction of fringe modulated images in the presence of noise involves choosing an optimal sized unitcell. The choice of the unit cell based on the size of the polarization domain and illumination level is analyzed using a bias-variance tradeoff to obtain the minimum root mean square error. A similar tradeoff study is used to analyze the choice of the band pass filters under various illumination levels. Finally, a sensitivity analysis of the ISIP is presented to explore the applicability of this device to detect low degrees of polarization in areas like remote sensing.
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Mu, Tingkui, Zeyu Chen, Chunmin Zhang, and Rongguang Liang. "Optimal design and performance metric of broadband full-Stokes polarimeters with immunity to Poisson and Gaussian noise." OPTICAL SOC AMER, 2016. http://hdl.handle.net/10150/622954.
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In this paper, the design, optimization and analysis of broadband full-Stokes polarimeters with immunity to both Poisson and Gaussian noise are presented. Different from the commonly-used optimization metrics such as, the condition number (CN), the equally weighted variance (EWV), or the polarimetric modulation efficiency (PME) for Gaussian noise, the optimally balanced condition for Poisson noise (BCPN) is, for the first time, proposed and used as a metric for the optimization of polarimeters. The numerical results show that the polarimeters optimized with the BCPN have immunity to both Poisson and Gaussian noise. The broadband polarimeters optimized from the BCPN are achromatic and have similar polarimetric modulation properties over the waveband, in contrast to the polychromatic polarimeters optimized from the CN, EWV and PME, whose polarimetric modulation properties vary with wavelength. (C) 2016 Optical Society of America
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Hudson, Derek Lavell. "Improving Accuracy in Microwave Radiometry via Probability and Inverse Problem Theory." Diss., CLICK HERE for online access, 2009. http://contentdm.lib.byu.edu/ETD/image/etd3244.pdf.
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Bleunven, Angel. "Contribution à la conception d'un système d'imagerie polarimétrique en vue d'applications pour la détection précoce du mélanome." Thesis, Brest, 2016. http://www.theses.fr/2016BRES0088/document.
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Le mélanome est un cancer rare de la peau qui se développe à partir des cellules responsables de la pigmentation : les mélanocytes. Depuis quelques années, nous observons une augmentation significative du nombre de personnes atteintes par cette maladie, de mauvais pronostic et très agressive (132 000 nouveaux cas chaque année dans le monde). Le taux de mortalité de ce cancer est très élevé en raison de la rapidité de propagation des cellules cancéreuse dans d’autres régions du corps. En France, on remarque un nombre relativement élevé de cas détectés, plus particulièrement en Bretagne. La tumeur se présente comme une tâche dont l’apparence est très proche du grain de beauté. Si elle est détectée suffisamment tôt, un prélèvement suffit à la guérison et les risques de récidives sont très faibles. En revanche, une fois que les métastases se propagent, les chances de survie à long terme sont très faibles. Malgré les récentes avancées en thérapie ciblée, les traitements du mélanome métastatique restent encore limités. En partenariat avec le groupe Malakoff Médéric, nous développons actuellement un système optique pour la détection précoce du mélanome cutané. Celui-ci est basé sur les propriétés de polarisation de la lumière. La thèse présente la conception du système, de l’étude de faisabilité jusqu’à l’étape finale d’étalonnage. Nous proposons également différents tests sur des échantillons de simulation. Ces derniers nous permettent de démontrer la corrélation qu’il existe entre les effets de polarisation et les modifications biologiques en cours lors du développement du mélanome. Cette étude préliminaire nous prépare aux expérimentations sur de vrais échantillonsMelanoma is a rare cancer that develops from the pigmentation cells of the skin. Recently, we notice a significant increase in the number of people affected by this aggressive disease with a poor prognosis (132 000 new cases each year worldwide). The mortality rate of this cancer is very high, which is due to the rapid spread of cancerous cells to other parts of the body. In France, there is a relatively high number of cases detected, especially in Britanny. The tumor is a spot which looks like a mole. If detected early, a levy is sufficient to healing and the risk of recurrence is very low. However, once metastasis spread, the long-term prognosis is very low. Despite recent advances in targeted therapy, the treatments of metastatic melanoma are still limited. In partnership with the Malakoff Mederic group, we are currently developing an optical system for early detection of cutaneous melanoma. It is based on the polarization properties of light. The PhD focuses on the design of the system, from the feasibility study to the final calibration. We also present various tests on samples of simulation. These allow us to demonstrate the correlation between the effects of polarization and biological changes during the development of melanoma. This preliminary study prepares us to experiments on real samples
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Brugés, Javier Mauricio. "Surface characterization methods for quality assessment of polyethylene-coated paperboard." Licentiate thesis, Mittuniversitetet, Institutionen för elektronikkonstruktion, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-41710.
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In manufacturing processes, the quality of a product often depends on its surface, and careful control of surface properties is critical to meet customer requirements. A thin layer of polyethylene (PE) is applied to paperboard to increase barrier functionality and high optical quality of the product. For PE-coated paperboard, product quality inspection is performed at the end of the manufacturing process by taking a portion of the reel to the laboratory for quality inspection. These associated offline characterization methods are destructive and time consuming and are representative of only a small portion of the product. The overall goal of this thesis is to provide new methods to characterize the Surface properties of PE-coated paperboard. Specifically, to determine imaging techniques for measuring surface parameters that affect its barrier functionality and surface roughness. In this thesis, two methods for surface characterization of PE-coated paperboard are presented to quantify the two most important product-related quality parameters, i.e. barrier functionality and optical quality, which are affected by the presence of defects in the coating and by the surface roughness of the product, respectively. First, a full-Stokes imaging polarimeter (FSIP) is used to detect the presence of PE-coated material and to distinguish between coated and uncoated samples at the pixel level. Second, a three-dimensional scanning electron microscope (3D SEM) is employed to calculate the Surface roughness of PE-coated paperboard. These surface characterization techniques offer an advantage over the industry standard due to the high speed and non-contact nature of the measurement, while increasing the throughput of the sample surface parameters studied. A classification accuracy of 99, 74% is achieved using a FSIP to distinguish between PE- and non-PE-coated paperboard at pixel level. Using the 3D SEM technique to measure the topography of PE-coated samples results in a faster method that is comparable in accuracy to a chromatic confocal microscope (CCM). The surface roughness measured with the 3D SEM differs from the standard method by up to 6% and good agreement with statistical parameters is found. In general, surface analysis of PE-coated is often a complex and difficult task for imaging techniques and suitable methods need to be evaluated for their sensitivity to measure the desired surface parameters. The presented characterization techniques inspect larger areas of PE-coated paperboard compared to current industry standards. These methods provide a quantitative solution for surface characterization to inspect the surface parameters necessary to assure the product’s quality.
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Panascí, Marco. "Vliv dlouhých optovláknových tras na polarizační stav světla a jejich využití pro napájení polarizačních senzorů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442367.
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This diploma thesis deals with the influence of long fiber optic paths on the polarization state of light and their use for powering polarization sensors. The aim of the diploma thesis was to design the arrangement of optical fiber components so that the polarization properties of light at the end of the path are further usable for sensory purposes. Four partial measurements with a long path (in a laboratory setting, laying in the ground, on a curtain, under the influence of external influence) and one measurement without a path under the influence of external influence were designed. The overall measurement results demonstrate that for the functional power supply of long-distance sensor systems, an existing single-mode fiber can be used (laid by laying in the ground), into which a light source for a given sensor system would be multiplexed. In the discussion, all types of measurements are analyzed and compared with each other. Finally, the overall result is summarized and applications are described in which such a sensor system could be used.
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Velič, Ladislav. "Měření vlastností polarizovaného světla na výstupu optovláknového senzoru." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-413106.
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Tsung-TseYang and 楊宗澤. "Extracting Optical Parameters of a Liquid Crystal Cell by Using Stokes Polarimetry." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/88765082506562998877.
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Li-HanLin and 林立恒. "Study on Glucose Concentration with Scattering Effect Based Upon Stokes-Mueller Polarimetry." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/82726317286712609716.
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碩士國立成功大學
機械工程學系
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A new scheme to measure the glucose concentration with scatters by polarimetry is proposed. Diabetics would benefit greatly from a device capable of providing continuous noninvasive monitoring of their blood glucose levels. The presence of optical activity object dissolved in an aqueous solution modifies the refractive index of the solution and therefore has an influence on the optical properties. Hence a physical correlation may exist between the optical scattering coefficient and concentration of optical activity substance. In this study, the measuring technique based on the Stokes-Mueller polarimetry to solve the Mueller matrices of a complex sample containing CB and depolarization is developed. Output Stokes vectors of four incident polarization states obtained from experiment can be compare to the corresponding value of the simulated Stokes vector, the difference is set as error function. Appling genetic algorithm, the minimum error can be found, the circular birefringence and depolarization which relate to the concentrations of glucose and scattering events in turbid media can be extracted, too. In addition, the Monte Carlo simulation can be used to numerically solve the problem of light propagation in turbid media. This method relies on repeated random sampling to obtain numerical results. The optical properties of interest are obtained from the statistical average of the photon properties. It is widely used in biomedical research to analyze propagation of light through the tissue.
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Jian-XiangLin and 林建翔. "Research of Measuring Glucose Concentration with Scattering Effect by Using Stokes-Mueller polarimetry." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/17057491597961811596.
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FitzGerald, William. "Broadband IR stokes polarimetry for the electro-optic characterization of cadmium zinc telluride." Thesis, 2017. https://dspace.library.uvic.ca//handle/1828/8900.
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The infrared portion of the electro-magnetic spectrum is a challenging region in which
to perform optical techniques, limited by both device efficiency and availability. In
this dissertation, a new optical technique is introduced to facilitate polarization state
measurement across the mid-IR. In addition, cadmium zinc telluride (CZT) is investigated
as a potential new material suitable for electro-optic devices which function in the mid-IR,
while also being characterized by other optical analysis methods.
Thin film interference is discussed as it relates to optical techniques and electronic
devices. A Stokes polarimeter is used to study the oxide development on the surface of
CZT electronic devices, and the effect of natural thin films on substrates used in optical
techniques is discussed. In particular, the impact of thin film interference on sum-frequency generation spectroscopy measurements of methyl group orientation are assessed.
An FTIR source operated in step-scan mode is used to create a broadband, IR Stokes
polarimeter which measures the polarization state of light from 2.5-11 μm simultaneously.
Its design, involving two photo-elastic modulators and an analyzer, and theory are described in detail. This instrument is demonstrated by measuring linearly polarized light, and is applied to the measurement of the refractive index dispersion of quartz from 2.5-4 μm, which goes beyond the limits of literature values.
Electro-optic crystals of CZT with electrodes of gold and indium are characterized
at each wavelength in the mid-IR in terms of their electro-optic effects and apparent
depolarization using the Stokes polarimeter. The material displays high-resistivity,
allowing it to be operated with up to 5 kV applied DC voltage. The linear electro-optic
effect is observed, but overall properties of the samples are found to be heavily dependent
on the choice of metal for the electrodes. With a high-work function electrode material
in gold, a large depletion region is created when high voltage is applied, which leads to a
gradient in electric field throughout the material. This causes a beam of light transmitted through it to experience a distribution of electro-optic behaviours, which leads to overall
depolarization of the light. Indium’s work function is lower than gold’s, and is closer to
that of CZT. With indium electrodes, the electric field is found to be more consistent, and
behaviour is much closer to ideal.
The electro-optic effect of CZT is also characterized with AC applied voltage in order
to assess its suitability to AC applied voltage applications. The power supply used for
this was limited to 60 Hz, which precludes a complete characterization in this regard, but
unexpected behaviour was seen. A methodology utilizing an oscilloscope and FTIR was
developed in order to more completely understand the material response, and divergent
behaviour with positive and negative voltage was found.Graduate
2018-12-18
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Cenacchi, Elena [Verfasser]. "Full stokes polarimetry with the Effelsberg 100-m radio telescope / vorgelegt von Elena Cenacchi." 2009. http://d-nb.info/1006640665/34.
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Yeng-ChengLiu and 劉彥成. "Spectroscopic Stokes Polarimetry Based on Fourier Transform Spectrometer and Phase Error Calibration in Michelson Interferometer." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/21116694324454881524.
Full textAbstract:
碩士國立成功大學
機械工程學系
102
Three methods are proposed for measuring the spectroscopic/monochromatic Stokes parameters using a Fourier transform spectrometer. In the first method, the parameters are extracted using an optical setup comprising a white light source, a polarizer set to 0°, a quarter-wave plate and a scanning Michelson interferometer. In the proposed approach, the parameters are extracted from the intensity distributions of the interferograms produced with the quarter-wave plate rotated to 0°, 22.5°, 45° and -45°, respectively. In the second approach, the interferograms of two-dimensional detection also can be simultaneously extracted via a pixilated phase-retarder and polarizer array made from photonic crystal on a high-speed CCD camera and a parallel read out circuit with a multi-channel analog to digital converter. Thus, a full-field and dynamic spectroscopic Stokes polarimetry without any rotating components could be developed. Finally, in the third method, the white light source is replaced by a monochromatic light source, the interferometer is removed, and a simple Stokes polarimetry is introduced in this study. The validity of the proposed methods is demonstrated both numerically and experimentally. To the authors’ knowledge, this could be the simplest optical arrangement in extracting the spectral Stokes parameters. Importantly, the latter two methods avoid the need for rotating components within the optical system and therefore provide an experimentally straightforward means of extracting the spectral Stokes parameters. In addition, the study is also proposed the compensation of phase distortion of beam splitter in Michelson interferometer. The method using Q, H, Q structure on the principle of compensation is proposed. Before phase errors is compensated you can confirm whether this model can be compensated using genetic algorithms, this method can greatly reduce the phase distortion errors of beam splitter.
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Wei-TingChen and 陳威廷. "Research of using new dynamic dual-wavelength Stokes-Mueller matrix polarimetry for non-invasive glucose measurement." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/r5k23q.
Full textAbstract:
碩士國立成功大學
機械工程學系
106
In this study, two different Stokes-Mueller polarimetry systems are proposed for extracting circular birefringence (CB) and depolarization index (Δ) of glucose solution. First system namely dual-wavelength Stokes Mueller polarimetry system utilizes two different wavelength laser sources (633nm and 532nm) and multiple linear regression (MLR) method to minimize the result deviation. Additionally, electro-optic modulators (EO) are used to reduce the system error caused by moving parts and manually adjustment. The resolution of measuring 2% phantom solution by this system is approximate 45 mg/dl. For second system, dynamic Stokes-Muller polarimetry system utilizes two electro-optic modulators to reduce the system error caused by moving parts and manually adjustment. The commercial Stokes polarimeter replaced the photo detector to simplify the system and the calibration process. The experiment results of 2% phantom solution show that the optical rotation angle (γ) increases linearly by changing of glucose concentration, while the depolarization index (Δ) decreases linearly by the changing of glucose concentration. The resolution of measuring 2% phantom solution is approximate 30 mg/dl. The practical applicability of the second system has been demonstrated by extracting optical rotation angle (γ), depolarization index (Δ) and glucose concentration of mice and human fingertip. The results of mice show that optical rotation angle (γ) increases linearly to the increasing of glucose concentration, while depolarization index (Δ) decreases linearly to the increasing glucose concentration. The estimated error of mice is approximately 60 mg/dl. For human fingertip test, the maximum error and minimum error between the proposed non-invasive method and invasive method are 47 mg/dl and 0 mg/dl, respectively. The deviation of the system for human fingertip test is 19 mg/dl. In Clarke error grid analysis, the percentages of results in Zone A and Zone B are 83.3%, 16.7%, respectively. The percentage of results in Zone (A+B) is 100%, whereas the percentage of results in Zones C, D and E are all 0%. It demonstrates that the data points from our system would not lead to inappropriate treatments for patients. In general, the proposed technique provides a potential tool for noninvasive glucose measurement in diabetes diagnosis application.
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Cookson, Christopher James. "Retinal Imaging: Acquisition, Processing, and Application of Mueller Matrix Confocal Scanning Laser Polarimetry." Thesis, 2013. http://hdl.handle.net/10012/7597.
Full textAbstract:
The focus of this thesis is the improvement of acquisition and processing of Mueller matrix polarimetry using a confocal scanning laser ophthalmoscope (CSLO) and the application of Mueller matrix polarimetry to image the retina. Stepper motors were incorporated into a CSLO to semi-automate Mueller matrix polarimetry and were used in retinal image acquisition. Success rates of Fourier transform based edge detection filters, designed to improve the registration of retinal images, were compared. The acquired polarimetry images were used to reassess 2 image quality enhancement techniques, Mueller matrix reconstruction (MMR) and Stokes vector reconstruction (SVR), focusing on the role of auto-contrasting or normalization within the techniques and the degree to which auto-contrasting or normalization is responsible for image quality improvement of the resulting images. Mueller matrix polarimetry was also applied to find the retardance image of a malaria infected retinal blood vessel imaged in a confocal scanning laser microscope (CSLM) to visualize hemozoin within the vessel. Image quality enhancement techniques were also applied and image quality improvement was quantified for this blood vessel.
The semi-automation of Mueller matrix polarimetry yielded a significant reduction in experimental acquisition time (80%) and a non-significant reduction in registration time (44%). A larger sample size would give higher power and this result might become significant. The reduction in registration time was most likely due to less movement of the eye, particularly in terms of decreased rotation seen between registered images. Fourier transform edge detection methods increased the success rate of registration from 73.9% to 92.3%. Assessment of the 2 MMR images (max entropy and max signal-to-noise ratio (SNR)) showed that comparison to the best CSLO images (not auto-contrasted) yielded significant average image quality improvements of 158% and 4% when quantified with entropy and SNR, respectively. When compared to best auto-contrasted CSLO images, significant image quality improvements were 11% and 5% for entropy and SNR, respectively. Images constructed from auto-contrasted input images were of significantly higher quality than images reconstructed from original images. Of the 2 other images assessed (modified degree of polarization (DOPM) and the first element of the Stokes vector (S0)), DOPM and S0 yielded significant average image quality improvements quantified by entropy except for the DOPM image of the RNFL. SNR was not improved significantly when either SVR image was compared to the best CSLO images. Compared to the best auto-contrasted CSLO images, neither DOPM nor S0 improved average image quality significantly. This result might change with a larger number of participants. When MMR were applied to images of malaria infected retinal slides, image quality was improved by 19.7% and 15.3% in terms of entropy and SNR, respectively, when compared to the best CSLO image. The DOPM image yielded image quality improvements of 8.6% and -24.3% and the S0 image gave improvements of 9.5% and 9.4% in entropy and SNR, respectively. Although percent increase in image quality was reduced when images were compared to initial auto-contrasted CSLO images, the final image quality was improved when auto-contrasting occurred prior to polarimetry calculations for max SNR and max entropy images. Quantitative values of retardance could not be found due to physical constraints in the CSLM that did not allow for characterization of its polarization properties and vibrational noise. Mueller matrix polarimetry used to find the retardance image of a malaria infected retina sample did yield visualization of hemozoin within the vessel but only qualitatively.
In conclusion, improvements in the acquisition and registration of CSLO images were successful in leading to considerably shorter experimentation and processing times. In terms of polarimetric image quality improvement techniques, when compared to the best CSLO image. A large proportion of the improvement was in fact due to partially or completely stretching the pixel values across the dynamic range of the images within the algorithm of each technique. However, in general the image quality was still improved by the Mueller matrix reconstruction techniques using both entropy and SNR to generate the CSLO retinal images and the CSLM imaged malaria infected sample. In the malaria sample, retinal blood vessel visualization was also qualitatively improved. The images yielded from Mueller matrix polarimetry applied to a malaria infected retinal sample localized hemozoin within the blood vessel, but a quantitative image of the phase retardance could not be achieved.
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Quoc-HungPhan and 潘國興. "Stokes-Mueller matrix polarimetry for biological sensing and characterization of optical/physical property of thin film with rough surface." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/97106698026952987008.
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"Metasurface-Based Optoelectronic Devices for Polarization Detection and Ultrafast Optical Modulation." Doctoral diss., 2020. http://hdl.handle.net/2286/R.I.62822.
Full textAbstract:
abstract: Optical metasurfaces, i.e. artificially engineered arrays of subwavelength building blocks supporting abrupt and substantial light confinement, was employed to demonstrate a novel generation of devices for circularly polarized detection, full-Stokes polarimetry and all-optical modulation with ultra-compact footprint and chip-integrability.
Optical chirality is essential for generation, manipulation and detection of circularly polarized light (CPL), thus finds many applications in quantum computing, communication, spectroscopy, biomedical diagnosis, imaging and sensing. Compared to natural chiral materials, chiral metamaterials and metasurfaces enable much stronger chirality on subwavelength scale; therefore, they are ideal for device miniaturization and system integration. However, they are usually associated with low performance due to limited fabrication tolerance and high dissipation mainly caused by plasmonic materials. Here, a bio-inspired submicron-thick chiral metamaterial structure was designed and demonstrated experimentally with high contrast (extinction ratio >35) detection of CPL with different handedness and high efficiency (>80%) of the overall device. Furthermore, integration of left- and right-handed CPL detection units with nanograting linear polarization filters enabled full-Stokes polarimetry of arbitrarily input polarization states with high accuracy and very low insertion loss, all on a submillimeter single chip. These unprecedented highly efficient and high extinction ratio devices pave the way for on-chip polarimetric measurements.
All-optical modulation is widely used for optical interconnects, communication, information processing, and ultrafast spectroscopy. Yet, there’s deficiency of ultrafast, compact and energy-efficient solutions all in one device. Here, all-optical modulation of light in the near- and mid-infrared regimes were experimentally demonstrated based on a graphene-integrated plasmonic nanoantenna array. The remarkable feature of the device design is its simultaneous near-field enhancement for pump and probe (signal) beams, owing to the localized surface plasmon resonance excitation, while preserving the ultrafast photocarrier relaxation in graphene. Hence, a distinct modulation at 1560nm with record-low pump fluence (<8μJ/cm^2) was reported with ~1ps response time. Besides, relying on broadband interaction of graphene with incident light, a first-time demonstration of graphene-based all-optical modulation in mid-infrared spectral region (6-7μm) was reported based on the above double-enhancement design concept. Relying on the tunability of metasurface design, the proposed device can be used for ultrafast optical modulation from near-infrared to terahertz regime.Dissertation/Thesis
Doctoral Dissertation Electrical Engineering 2020
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Wang, Wen-Zhe, and 王文哲. "Visualizing Skin Lesions with Stokes’ Polarimeter Based Second Harmonic Generation Microscopy." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/92857260609353417350.
Full textAbstract:
碩士國立陽明大學
生醫光電研究所
101
Dermatological diagnosis is usually done by visual examination or detailed biopsies with microscopy on the targeted specimen. The processes usually lack quantitative analysis, and may be time consuming if tissue culturing is required. This study focuses on the biopsy of scar tissues of human skin, including normal, hypertrophic, and keloid tissues, by analyzing the polarization states of second harmonic signals from the tissues with the novel four-channel Stokes’ polarimeter. A mode-locked Ti-sapphire laser, which generated 200 fs ultra-short pulses, is used to induce second harmonic signal from the collagen of the skin tissues. In this way, the potential photo-toxicity on fluorophores is greatly reduced. The samples are irradiated with the incident beam of various polarization states. The resulting polarization parameters reconstructed from the SHG signals reveal unique collagen arrangements in the tissues. Our results show that the different skin lesions are clearly distinguishable through the polarization imaging of the collagen structure. The noninvasive and enhanced contrast enabled by polarization has the potential for in-depth biomedical analysis and may find invaluable applications in clinical diagnosis.
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Thi-Thu-HienPham and 範秋賢. "Characterization on effective optical parameters of anisotropic materials and turbid media using Stokes polarimeter." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/17040847171982627902.
Full textAbstract:
博士國立成功大學
機械工程學系碩博士班
100
A decoupled analytical technique based on the Mueller matrix method and the Stokes parameters is proposed for extracting nine effective parameters in linear birefringence (LB), linear dichroism (LD), circular birefrinegence (CB), and circular dichroism (CD), linear depolarization (L-Dep), and circular depolarization (C-Dep) properties of turbid media. In contrast to existing analytical models, the nine effective parameters are extracted in a totally decoupled manner. It is noted that the recent related studies did not show enough nine parameters of characteristics of bio-sample. The error and resolution analysis of the proposed approach is demonstrated by extracting the effective parameters of optical samples with varying degrees of linear / circular birefringence, linear / circular dichroism, and linear / circular depolarization given an assumption of errors ranging from ±0.005 in the values of the output Stokes parameters. The results confirm the ability of the proposed method to yield full-range measurements of all the effective optical parameters. The validity of the proposed measurement method in testing different samples is proved. Also, the experimental results have showed that the CB property of two types polystyrene microspheres with containing D-glucose and de-ionized water with containing D-glucose is affected by the distance between the samples and detector. The decoupled nature of the analytical model yields several important advantages, including an improved accuracy and the ability to extract the parameters of optical samples with only linear birefringence, circular birefringence, linear dichroism, circular dichroism or depolarization property without using compensation technique or pretreatment. Moreover, by decoupling the extraction process, the “multiple solutions” problem inherent in previous models presented by the current group is avoided. As authors’ knowledge, this methodology could be the most comprehensive algorithm in extracting all nine effective parameters in decoupling in turbid media. When using an optical fiber probe to measure the properties of anisotropic optical materials, some form of polarization controller is required to compensate for the inherent birefringence and diattenuation properties of the fiber. The experimental settings of the optical components within the polarization controller are generally determined on a trial-and-error basis; resulting in a lengthy experimentation process. Accordingly, in the present study, a method is proposed for calculating in advance the precise controller settings required to guarantee the formation of a free-space condition. In the proposed approach, the effective optical parameters of the optical fiber are determined using this analytical method, and the optimal settings of the polarization controller are then determined using a genetic algorithm. It is shown that the proposed approach enables a free-space condition to be achieved for the common polarization controller. The practical applicability of the proposed approach is demonstrated by remotely and absolutely measuring the linear birefringence and linear diattenuation properties of a quarter-wave plate and a polarizer, respectively.
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Lu, Yun-Xiang, and 陸韻翔. "Monitoring Thermal Denaturation of Starch granules by Stokes’ Polarimeter Based Second Harmonic Generation Microscopy." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/43338501727184308364.
Full textAbstract:
碩士國立陽明大學
生醫光電研究所
101
Starch is one of the major components in our daily diet. It is also a natural second harmonic (SH) generator, with amylopectin as the active component. The molecular structure and optical activity of starch may well be reflected by SH. In this work, we investigated the polarization states of SH from starch by 4-channel based Stokes’ polarimeter. The change of SH and its polarization states are monitored throughout the denaturation processes for both dry and hydrated starch. It was found that SH disappears at the gelatinization temperature. The results are consistent with those from differential scanning calorimeter (DSC) and the loss of birefringence from hydrated starch during heating. For comparison, SH from dry starch decreases gradually. When comparing the data of DSC and SH from starch during heating, the endothermic peak at 65 degree is observed for hydrated starch, at which the intermolecular bonds in amylopectin are broken down to result in the disruption of the concentric symmetrical structure. The change in structure is reflected by SH and the corresponding polarization states and is verified by scanning electric microscopy (SEM). In SEM micrographs, the dry starch granules show only destroyed surface, while the hydrated ones exhibits near total disintegration of granular structures due to gelatinization, reflecting the fact that water is crucial for the cooking of rice.
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Fernandes, Pedro Francisco Santos Braga. "Polarimetric LiDAR for target characterization aiming at autonomous driving implementations." Master's thesis, 2020. http://hdl.handle.net/1822/73643.
Full textAbstract:
Dissertação de mestrado integrado em Engenharia Física (área de especialização em Dispositivos, Microssistemas e Nanotecnologias)LiDAR is an active sensor, used to measure distances. By illuminating obstacles and measuring retro-reflected light, LiDAR is able to measure the distance to a particular obstacle, as well as predict the shape of that obstacle. In autonomous driving, the high precision and accuracy of LIDAR is an enormous asset for decision making and safety. The fact that it is a fundamental technology for autonomous driving means that large companies are allocating resources (monetary and intellectual) to their development. The project in which this dissertation is inserted aims to use the concept of polarization of light in the LIDAR system, in order to allow the classification of targets and help their recognition. In the course of this work, different Mueller Polarimeters were built to consider and evaluate the importance and usefulness of polarization in the classification of materials. Two of the setups were developed, with a 1550 nm wavelength laser, in the facilities of the School of Sciences of the University of Minho, being different by using distinct polarimetric components to generate and analyse states of polarization: quarter wave plates or liquid crystals variable retarder and linear polarizers . The two 1550 nm setups and the obtained polarimetric information are described in this document. The work presented here also involved the construction of a fourth setup: a LIDAR demonstrator, whose objective was not only to measure distances with high precision and accuracy, but also to introduce polarimetric components and to recognize the importance of using polarization in the differentiation of materials. The results obtained in this work allow us to conclude that polarization at 1550 nm of wavelength has very significant importance in the classification and recognition of road scene objects. Moreover, a Polarization 1D LiDAR at a 1550nm is capable of distinguishing between at least some relevant materials of great importance in autonomous vehicle safety. Therefore, it is proposed to continue this path of work on polarization in LIDAR systems, in order to increase the capabilities of recognizing the environment, in the context of autonomous driving.
O LiDAR é um sensor ativo, utilizado para medir distâncias. Iluminando os obstáculos e medindo a luz retro-refletida, o LiDAR é capaz de medir a distância até um determinado obstáculo, bem como de prever a forma desse mesmo obstáculo. Na condução autónoma, a elevada precisão e exatidão do LIDAR constituem uma enorme mais-valia para a tomada de decisões e para a segurança. O facto de ser uma tecnologia fundamental para a condução autónoma faz com que grandes empresas estão a alocar recursos ao seu desenvolvimento. O projeto em que esta dissertação se insere tem como objetivo utilizar o conceito de polarização da luz no sistema LIDAR, a fim de permitir a classificação de alvos e facilitar o reconhecimento dos mesmos. No decorrer deste trabalho, foram construídos três diferentes Polarímetros de Mueller para considerar e avaliar a importância e utilidade da polarização na classificação de materiais. Dois setups foram desenvolvidos, com lasers de 1550 nm, nas instalações da Escola de Ciências da Universidade do Minho, sendo estes diferenciados pela utilização de diferentes componentes polarimétricos na geração e análise de estados de polarização: lâminas de quarto de onda ou cristais líquidos de atraso variável e polarizadores lineares. Os dois setups referidos e a informação polarimétrica obtida são apresentados neste documento. O trabalho aqui apresentado envolveu, também, a construção de um quarto setup demonstrador de LIDAR, cujo objetivo era não só medir distâncias com elevada precisão e exatidão, como também introduzir componentes polarimétricas e reconhecer a importância da utilização de polarização na diferenciação de materiais. Os resultados obtidos neste trabalho permitem concluir que a polarização, a um comprimento de onda de 1550 nm, tem uma importância muito significativa na classificação e reconhecimento de objetos. Conclui-se também que, um LiDAR de polarização a 1550 nm é capaz de distinguir entre pelo menos alguns materiais de elevada importância para a segurança de veículos autónomos. Assim, propõe-se que seja prosseguida a linha de trabalho na polarização em sistemas LIDAR, de forma a aumentar as capacidades de reconhecimento do ambiente, em contexto de condução autónoma.
This work is supported by European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project nº 037902; Funding Reference: POCI-01-0247-FEDER-037902].
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Wen-HsiangHsieh and 謝文翔. "New Stokes-parameter-based Polarimeter for Determination of Optical Properties of Thin Film and Twisted Nematic Liquid Crystal Cell." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/58356005855369643179.
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Chih-Chao, Chang, and 張智超. "Using New Electro-Optically Modulated Circular Heterodyne Interferometer and Rotating-Wave-Plate Stokes Polarimeter Respectively for Measuring the Optical Rotation Angle." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/07929282429436386855.
Full textAbstract:
碩士遠東科技大學
機械研究所
96
This paper develops two optical systems to measure the optical rotation angle of a chiral medium such that its concentration can be proportionally extracted, one is a new electro-optically modulated circular heterodyne interferometer using the phase-lock technique and the other is based on the Stokes-Mueller formalism and a rotating-wave-plate Stokes polarimeter. The measured samples are not only the solid chiral medium such as a half-wave plate and the chiral fluid as glucose solutions, but also the solid chiral medium manufactured by the sol-gel method. As compared to the others, the two proposed polarimeters have fewer optical elements, are more compact in configuration, and use a simple methodology to achieve rotation angle, respectively. Using the new electro-optically modulated circular heterodyne interferometer and lock-in technique, the measurement results shows that the average relative error of the measured optical rotation angle in a half-wave is 0.00284deg, with a correlation coefficient of 0.9999975 between the measured and theoretical rotation angles, it pointed out that there exists a good linear response. In addition, from the experimental results of the glucose solution with a concentration of 0-1.2g/dl and the increment of 0.2g/dl, we can know that the standard error of the measured optical rotation is 0.005275, the correlation coefficient between the reference concentration value and measured optical rotation is calculated as 0.99915. This measurement system can measure the smallest concentration of glucose solution 0.2g/dl, the resolution of measured rotation angle can be reached as 0.0028deg. Moreover, from the experimental result based on the Stokes-Mueller formalism and a rotating-wave-plate Stoker polarimeter, it shows that the average relative error of the measured optical rotation angle in a half-wave is 1.16 %. A correlation coefficient of 0.999979 is determined and indicated that there is a good linear response. In addition, from the experimental results of the glucose solution with a concentration of 0-1.2g/dl and the increment of 0.2g/dl, we can know that the correlation coefficient is 0.99951 and the average relative error of the measured rotation angle is 3.78%. In the repeatability experiments of glucose solution of 0.2g/dl, the average relative error of the measured optical rotation angle is 8.86%. Furthermore, from the experimental result of the solid chiral medium manufactured by sol-gel method, a chiral sol-gel containing the griseofulvin within the PMMA solution produced by the first manufacture method, the concentration of griseofulvin is from 0 to 0.0665g/ml and the increment is 0.0133g/ml, it shows that a correlation coefficient is 0.99969, the standard deviation of measured rotation angle is 0.0007deg, and the average relative error of the measured rotation angle is 3.42%. On the other hand, from the other test of a chiral sol-gel containing the griseofulvin within TEOS solution produced by the second manufacture method, it indicates that when the concentration of griseofulvin is 0.014g/ml, the average relative error of the measured rotation angle is 8.82%