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Conference on current developments in Lens design and optical engineering XvIII

作者： Baril, Alexandre Thibault, Simon Galstian, Tigran Univ Laval Dept Phys Genie Phys & Opt Ctr Opt Photon & Laser 2375 Rue Terrasse Quebec City PQ G1V 0A6 Canada

ISBN: (纸本)9781510612082;9781510612075

Now that LEDs have massively invaded the illumination market, a clear trend has emerged for more efficient and targeted lighting. The project described here is at the leading edge of the trend and aims at developing an evaluation board to test smart lighting applications. This is made possible thanks to a new liquid crystal light modulator recently developed for broadening LED light beams. The modulator is controlled by electrical signals and is characterized by a linear working zone. This feature allows the implementation of a closed loop control with a sensor feedback. This project shows that the use of computer vision is a promising opportunity for cheap closed loop control. The developed evaluation board integrates the liquid crystal modulator, a webcam, a LED light source and all the required electronics to implement a closed loop control with a computer vision algorithm.

关键词： optical systems Illumination closed loop vision system spatial light modulator

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design of off-axial Gregory telescope design with freeform mirror corrector 18

Design of off-axial Gregory telescope design with freeform m...

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Conference on current developments in Lens design and optical engineering XvIII

作者： Bazhanov, Yu. vlakhko, v. Corp Precis Syst & Instruments 53 Aviamotornaya Str Moscow 111024 Russia Dynaoptics 8 Boon Lay Way Singapore 609964 Singapore

ISBN: (纸本)9781510612082;9781510612075

In this paper a well-known approach is used for calculation of off-axis three-mirror telescope. It includes usage of conic cross-sections properties, each of the sections forming a stigmatic image. To create a compact optical system, a flat mirror aberration corrector is introduced, which is at later stage transformed into a free-form surface in order to compensate field aberrations. Similarly, one can introduce such a corrector in finalized layout for its further optimization and getting a suitable form, including the conversion of multimirrors axial optical system into decentered one. As an example, off-axial Gregory telescope embodiment is used for infrared waveband region, due to the fact that, unlike the Cassegrain telescope, it provides a real exit pupil, and usage of the mirror corrector brings several advantages. Firstly, this feature may be used to include cold stop or adaptive mirror in the exit pupil, wherein corrector is introduced into a converging beam before the focus of the first mirror. Secondly, when placing corrector in the exit pupil of the optical system it is possible to eliminate high and low order aberrations of center point, which in turn improves optical system f-number, and minimize field aberrations. As another example, off-axial Ritchey-Chretien telescope embodiment is used as a good fit for visible region systems. Analysis and calculation results of optical systems with free-form correctors with surfaces, defined by Power polynomial series are presented in this paper. Advantages of different freeform surfaces usage depends on optical system layouts specifics.

关键词： Mirrors Telescopes Aberration theory Infrared telescopes Lens design Image analysis Infrared radiation optical design optical instrument design Telescope design

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Whole Wheat and Bran Cereal Affects Microbiome Stability

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current developments in Nutrition 2021年 5卷 5141162-5141162页

作者： Johnson, Abigail Houtti, Mo Saboe, Anna Koecher, Katie Menon, Ravi Knights, Dan Division of Epidemiology &amp Community Health School of Public Health University of Minnesota Minneapolis MN Department of Computer Science and Engineering University of Minnesota Minneapolis MN BioTechnology Institute College of Biological Sciences University of Minnesota Bell Institute of Health and Nutrition General Mills Inc.

AbstractObjectivesHealth outcomes in previous fiber intervention studies have been variable, potentially due to differences in gut microbiome composition. This study aimed to determine if the effect of fiber intervention on the microbiome differs by initial microbiome or the quantity of fiber provided. MethodsThis study was designed as a randomized, un-blinded, cross-over trial of fiber cereal dosage. The cross-over design tested the effect of two 2-week long interventions with a High (28g) and Low (14g) level of daily supplemental fiber from whole wheat and bran cereal. Analysis was also completed on the overall study as a single arm, non-randomized, intervention of fiber cereal. The study enrolled 31 healthy adults. The microbiome was assessed at baseline and after intervention for changes in diversity, composition, and stability. ResultsAcross all individuals, fiber intervention increased microbiome alpha-diversity (paired t-test, P = 0.047), but the microbiome was otherwise resistant to the effects of the intervention. Increasing fiber dose (High v. Low) was not associated with consistent changes in beta-diversity (linear mixed models). Approximately 20% of subjects were identified as responders based on beta diversity effect size. At baseline, responders had higher Prevotella copri and lower Bacteroides abundance than non-responders (Wilcoxon rank sum, qval < 0.05). In responders, fiber intake caused increased abundance of Bacteroides and Alistipes and reduced Prevotella (paired Wilcoxon, q < 0.2). In all subjects, fiber intervention decreased microbiome stability (paired Wilcoxon signed rank test, P = 0.006). In responders, there was a significant effect of the fiber level on stability, with higher fiber further lowering stability (linear mixed model, P = 0.05). ConclusionsOur data suggest a responder/non-responder microbiome signature for this whole wheat and bran fiber cereal. We find that many effects were not additive by dosage level. Overall, microbiome d

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Introducing the quantum efficiency of fluorescence of SCHOTT optical glasses 18

Introducing the quantum efficiency of fluorescence of SCHOTT...

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Conference on current developments in Lens design and optical engineering XvIII

作者： Jedamzik, Ralf Elsmann, Frank Engel, Axel Petzold, Uwe Pleitz, Jana Schott AG D-55122 Mainz Germany

ISBN: (纸本)9781510612082;9781510612075

The fluorescence of optical glasses is a property that needs to be taken into account in optical designs for life science applications. Many optical glasses from SCHOTT show a very low intrinsic or auto-fluorescence. The fluorescence depends mainly on the applied excitation wavelength and the optical glass type. The fluorescence of optical glasses is usually defined as the quotient of the integral of the emission spectrum with the integral of the emission spectrum of a reference glass. This definition does not give any information about the actual quantum efficiency of the fluorescence. In this presentation recent data on the integral fluorescence of SCHOTT optical glasses are presented. Additionally, first measurements of the quantum efficiency of SCHOTT optical glasses are presented and compared to the standard method.

关键词： Glasses Luminescence Quantum efficiency Biomedical optics Life sciences Space telescopes visual optics Lithography Microscopy optical design

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design and Characterization of High-current optical Darlington Transistor for Pulsed-Power Applications

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IEEE TRANSACTIONS ON ELECTRON DEvICES 2017年第3期64卷 769-778页

作者： Mojab, Alireza Mazumder, Sudip K. Univ Illinois Dept Elect & Comp Engn Lab Energy & Switching Elect Syst Chicago IL 60607 USA

A high-current and low on-state voltage optical Darlington transistor (ODT) is developed in this paper for high-power applications. The structure of this device includes a two-stage Darlington transistor in which the first stage is triggered optically using an infrared laser of an 808-nm wavelength. The photogenerated current in the first stage drives the second stage of the ODT for current amplification. The ON-state voltage of the proposed two-stage ODT is found to be 1.12 v at 50 A. The results show that a single-pipe laser with a low optical power of 2W is sufficient to trigger this high-current optical switch. This can give us more flexibility to achieve an optimal tradeoff between the ON-state voltage and delay times. The experimental results show that the ODT has a breakdown voltage of 70 v and can operate at frequencies higher than 10 kHz. Thismakes it potentiallysuitable as an optical gate driver for applications including but not limited to pulsed-power and series-connectionof power semiconductor devices for voltage scaling, and as an auxiliary optical-triggering device for anode-or even gate-current odulation of a high-frequency and high-power all-optical emitter turn-OFF thyristor.

关键词： Long-wavelength laser illumination optical Darlington transistors (ODTs) series connection of power semiconductor devices single-bias all-optical emitter turn-OFF (ETO) thyristor wide-bandgap power semiconductor devices

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optical spherometer for measuring large curvature radii of convex surfaces 18

Optical spherometer for measuring large curvature radii of c...

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Conference on current developments in Lens design and optical engineering XvIII

作者： Alvarado Martinez, Jorge de Jesus vazquez y Montiel, Sergio Camacho Bello, Cesar Joel Univ Politecn Tulancingo Tulancingo Hgo Mexico Univ Interserrana Estado Puebla Puebla Mexico

ISBN: (纸本)9781510612082;9781510612075

Measuring large curvature radii of convex surfaces with high precision is a challenge because the spherometer's focus must be positioned at the apex of the surface and at the center of curvature of the surface by moving the surface or the spherometer. If the radius of curvature is larger than the back focus of spherometer, then measurement is not possible. In this work, we propose to use the FOCOIvA system1 to move the focus of the spherometer in longitudinal way without modifying the f number by moving two lenses inside it, with this mechanism it is possible to measure radii of curvature of several meters in length. The curves of movement of the lenses and the optical parameters of the lenses that compose the spherometer are presented.

关键词： optical design spherometer radii of curvature convex surfaces

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Advanced Luminance Modeling of Light Sources for Simulation and Computational Purposes of Lighting Parameters 7

Advanced Luminance Modeling of Light Sources for Simulation ...

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7th Lighting Conference of the visegrad Countries, LUMEN v4 2018

作者： Slominski, Sebastian Faculty of Electrical Engineering Lighting Technology Division Warsaw University of Technology Electrical Power Engineering Institute Warsaw Poland

ISBN: (纸本)9781538679234

The last decade is the time of a very dynamic development of lighting technology. This development covers many areas that complement each other. The development of light sources, luminaires, measurement techniques and design methods make it necessary to develop new, effective tools to support the design and analysis of lighting equipment. In lighting technology, the most common analysis is made of such parameters as the illuminance, luminance distribution and discomfort glare, inseparable from the specificity of modern light sources. A characteristic feature of almost all of them is high luminance, on the level of 107- 108cd/m2. High luminance facilitates the design of very precise optical systems, but also it is strongly associated with the possibility of discomfort associated with glare. current methods of glare analysis in simulation software are related to conversion to the average luminance value of the luminaire, saved as simplified light parameters in electronic files (IES, LDT or similar). currently the calculations take place as a result of calculation ratio the value of luminous intensity in a given direction and the surface area of the dimension of the luminaires in the same direction. This can lead to a significant understatement of the luminance of the luminaire in any situation where luminous intensity comes from the heterogeneous luminance distribution on the surface of the luminaire. This situation most often occurs in luminaires with high-luminance light sources with a reflector system and in the case of multi-source luminaires with lenses - eg multi-LED luminaires. The paper presents advanced methods of luminance modelling of light sources developed as a result of digital measurements of luminance distributions. A comparative analysis of the accuracy of the simulation calculations of the analytical lighting fixture model will be presented. The results will be compared to the classic ray tracing methods used in currently used models. © 2018 IEEE.

关键词： Light sources

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Mauna Kea Spectroscopic Explorer (MSE): a preliminary design of multi-object high resolution spectrograph 7

Mauna Kea Spectroscopic Explorer (MSE): a preliminary design...

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Conference on Ground-Based and Airborne Instrumentation for Astronomy vII

作者： Zhang, Kai Zhou, Yifei Tang, Zhen Saunders, Will venn, Kim A. Shi, Jianrong McConnachie, Alan W. Szeto, Kei Wang, Lei Zhu, Yongtian Hu, Zhongwen Chinese Acad Sci Natl Astron Observ Nanjing Inst Astron Opt & Technol Nanjing 210042 Jiangsu Peoples R China Chinese Acad Sci Key Lab Astron Opt & Technol Nanjing Inst Astron Opt & Technol Nanjing 210042 Jiangsu Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China Australian Astron Observ N Ryde NSW 2113 Australia Univ Victoria Victoria BC V8P 5C2 Canada Chinese Acad Sci Natl Astron Observ China Beijing 100012 Peoples R China CFHT Corp Kamuela HI 96743 USA Natl Res Council Canada Victoria BC V9E 2E7 Canada

ISBN: (数字)9781510619586

ISBN: (纸本)9781510619586

The Maunakea Spectroscopic Explorer (MSE) project will transform the CFHT 3.6m optical telescope to a 10m class dedicated multi-object spectroscopic facility, with an ability to measure thousands of objects with three spectral resolution modes respectively low resolution of R approximate to 3,000, moderate resolution of R approximate to 6,000 and high resolution of R approximate to 40,000. Two identical multi-object high resolution spectrographs are expected to simultaneously produce 1084 spectra with high resolution of 40,000 at Blue (401-416nm) and Green (472-489nm) channels, and 20,000 at Red (626-674nm) channel. At the Conceptual design Phase (CoDP), different optical schemes were proposed to meet the challenging requirements, especially a unique design with a novel transmission image slicer array, and another conventional design with oversize volume Phase Holographic (vPH) gratings. It became clear during the CoDP that both designs presented problems of complexity or feasibility of manufacture, especially high line density disperser (general name for all kinds of grating, grism, prism). At the present, a new design scheme is proposed for investigating the optimal way to reduce technical risk and get more reliable estimation of cost and timescale. It contains new dispersers, F/2 fast collimator and so on. Therein, the disperser takes advantage of a special grism and a prism to reduce line density on grating surface, keep wide opening angle of optical path, and get the similar spectrum layout in all three spectral channels. For the fast collimator, it carefully compares on-axis and off-axis designs in throughput, interface to fiber assembly and technical risks. The current progress is more competitive and credible than the previous design, but it also indicates more challenging work will be done to improve its accessibility in engineering.

关键词： Maunakea Spectroscopic Explorer Multi-object Spectrograph High Spectral Resolution Grism

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New tools for the design of freeform mirrors 18

New tools for the design of freeform mirrors

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Conference on current developments in Lens design and optical engineering XvIII

作者： Dilworth, Donald C. Opt Syst Design Inc POB 247 East Boothbay ME 04544 USA

ISBN: (纸本)9781510612082;9781510612075

Advances in manufacturing and measuring technology are making the use of freeform mirrors more practical than in the recent past. New degrees of freedom make it possible for designers to improve image quality while increasing the field of view and avoiding obscurations. But other issues arise when one designs a system with several mirrors, particularly packaging and clearance concerns: one must ensure that none of the mirrors gets in the way of the beam from any of the others, and one must consider the coordinate system in which the shapes are defined and in which they are measured, which are not necessarily the same. Addressing these concerns requires new computational tools.

关键词： Freeform aspheric mirrors beam clearance at mirrors

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Efficient green electroluminescence from 1,3-diphenyl-1H-pyrazolo[3,4-b]quinoxaline dyes in dye-doped polymer based electroluminescent devices

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DYES AND PIGMENTS 2018年 151卷 380-384页

作者： Gasiorski, P. Matusiewicz, M. Gondek, E. Pokladko-Kowar, M. Armatys, P. Wojtasik, K. Danel, A. Uchacz, T. Kityk, A. v. Czestochowa Tech Univ Fac Elect Engn Al Armti Krajowej 17 PL-42200 Czestochowa Poland Cracow Univ Technol Inst Phys Podchorazych 1 PL-30084 Krakow Poland AGH Univ Sci & Technol Fac Phys & Appl Comp Sci Al A Mickiewicza 30 PL-30059 Krakow Poland Univ Agr Inst Chem Dept Food Technol Ul Balicka 122 PL-30149 Krakow Poland Jagiellonian Univ Fac Chem Gronostajowa 2 PL-30387 Krakow Poland

We demonstrate several polymer based electroluminescent devices with active poly(N-vinylcarbazole) (PvK) layer doped with diphenylpyrazoloquinoxaline (PQX) dyes, RPQX, with lateral substituent R = Me, MeO, F or Cl. The electronic properties of these fluorescence emitters and relevant electroluminescence devices are characterized by optical spectroscopy techniques. The first absorption bands of the RPQX dyes considerably overlap with the fluorescence emission band of the host PvK matrix resulting in efficient radiative energy transfer between them. Using the measured electroluminescent spectra the emission color is characterized in CIE 1931 XYZ color space. The electroluminescence devices with a dye-doped active layer PvK:RPQX (R = Me, MeO, F or Cl) emit light with different shades of green color. The electroluminescent performance is characterized in terms of current efficiency determined from the luminance-current-voltage measurements. Depending on the fluorescent dopant it ranges from about 0.5 to above 2.2 cd/A. Such efficiency has been achieved on a simple dye doped device configuration without significant optimization. Accordingly, RPQX dyes may be considered as prospective fluorescence emitters for electroluminescent applications. The measured spectral characteristics of RPQX fluorescent emitters and relevant electroluminescent devices are compared with quantum-chemical DFT/TDDFT calculations based on re-parameterized long-range corrected functional and corrected linear response solvation. Relevant analysis, due to its good performance and predicability, appears to be helpful not only for understanding of the, origin of electronic transitions, but may serve as useful tool for chemical engineering dealing with design and synthesis of novel organic dyes for optoelectronic applications.

关键词： Pyrazoloquinoxaline dyes optical absorption spectra Electroluminescence spectra Electroluminescent devices OLEDs DFT/TDDFT calculations

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