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High-brightness polarized light-emitting diodes

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light(Science & Applications) 2012年第1期1卷 72-78页

作者： Elison Matioli Stuart Brinkley Kathryn M Kelchner Yan-Ling Hu Shuji Nakamura Steven DenBaars James Speck Claude Weisbuch Department of Electrical Engineering and Computer Science Massachusetts Institute of TechnologyCambridgeMAUSA Department of Electrical and Computer Engineering University of CaliforniaSanta BarbaraCAUSA Materials Department University of CaliforniaSanta BarbaraCAUSA Laboratoire de Physique de la Matie`re Condense´e CNRSEcole PolytechniquePalaiseauFrance

light-emitting diodes are becoming the alternative for future general lighting applications,with huge energy savings compared to conventional light sources owing to their high efficiency and *** light sources would largely enhance the efficiency in a number of applications,such as in liquid-crystal displays,and also greatly improve contrast in general illumination due to the reduction in indirect ***,we demonstrate light-emitting diodes presenting high-brightness polarized light emission by combining the polarization-preserving and directional extraction properties of embedded photonic-crystals applied to non-polar gallium nitride.A directional enhancement of up to 1.8-fold was observed in the total polarized light emission together with a high polarization degree of 88.7%at 465 *** discuss the mechanisms of polarized light emission in non-polar gallium nitride and the photonic-crystal design rules to further increase the light-emitting diode *** work could open the way to polarized white-light emitters through their association with polarization-preserving down-converting phosphors.

关键词： GaN LEDs m-plane polarized light

A different view： sensory drive in the polarized-light realm

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Current Zoology 2018年第4期64卷 513-523页

作者： Thomas W. CRONIN Department of Biological Sciences University of Maryland Baltimore MD 21250 USA

Sensory drive, the concept that sensory systems primarily evolve under the influence of environmen tal features and that animal signals are evolutionarily shaped and tuned by these previously existing sensory systems, has been thoroughly studied regarding visual signals across many animals. Much of this work has focused on spectral aspects of vision and signals. Here, I review work on polarized light signals of animals and relate these to what is known of polarization visual systems, polarized light aspects of visual scenes, and polarizationrelated behavior （e.g., orientation, habitatfinding, contrast enhancement）. Other than the broad patterns of scattered polarized light in the sky, most po larization in both terrestrial and aquatic environments results from either reflection or scattering in the horizontal plane. With overhead illumination, horizontal features such as the surfaces of many leaves or of air： water interfaces reflect horizontal polarization, and water scatters horizontally polar ized light under most conditions. Several animal species have been demonstrated to use horizontally polarized light fields or features in critical aspects of their biology. Significantly, most biological sig nals are also horizontally polarized. Here, I present relevant polarizationrelated behavior and discuss the hypothesis that sensory drive has evolutionarily influenced the structure of polarization signals. The paper also considers the evolutionary origin of circular polarization vision and circularly polar ized signals. It appears that this class of signals did not evolve under the influence of sensory drive. The study of signals based on polarized light is becoming a mature field of research.

关键词： animal communication polarized light sensory drive vision visual signal

Dissociation of singlet excitons dominates photocurrent improvement in high-efficiency non-fullerene organic solar cells

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Nano Research Energy 2024年第1期3卷 30-37页

作者： Qicong Li Shizhong Yue Zhitao Huang Chao Li Jiaqian Sun Keqian Dong Zhijie Wang Kong Liu Shengchun Qu Yong Lei Key Laboratory of Semiconductor Materials Science Beijing Key Laboratory of Low Dimensional Semiconductor Materials and DevicesInstitute of SemiconductorsChinese Academy of SciencesBeijing 100083China China Electronics Standardization Institution Beijing 100007China Fachgebiet Angewandte Nanophysik Institut für Physik&IMN MacroNanoTechnische Universität IlmenauIlmenau 98693Germany

In organic solar cells,the singlet and triplet excitons dissociate into free charge carriers with different mechanisms due to their opposite spin ***,the ratio of the singlet and triplet excitons directly affects the *** methods were used to optimize the performance of the low-efficiency solar cell by improving the ratio of triplet excitons,which shows a long diffusion *** we observed that in high-efficiency systems,the proportion of singlet excitons under linearly polarized light excitation is higher than that of circularly polarized *** the singlet charge transfer state has lower binding energy than the triplet state,it makes a significant contribution to the charge carrier generation and enhancement of the ***,the positive magnetic field effect reflects that singlet excitons dissociation plays a major role in the photocurrent,which is opposite to the case of low-efficiency devices where triplet excitons dominate the photocurrent.

关键词： polarized light organic solar cell high efficiency singlet/triplet exciton

Combined application of extended depth of field imaging, image stitching and polarized microscopy techniques in identification of Spatholobus suberectus

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Chinese Herbal Medicines 2020年第4期12卷 367-374页

作者： Ying-xian Ma Chayanis Sutcharitchan Xiao-die Li Qian Meng Xin Wang Shen Ji Ya-jun Cui Shanghai University of Traditional Chinese Medicine Shanghai 201203China Chulalongkorn University Bangkok 10330Thailand Shanghai Institute for Food and Drug Control Shanghai 201203China

Objective:As traditional techniques for microscopic identification of Chinese medicines currently lack objective and high-quality reference images,here we developed a systemic procedure to be used in microscopic identification of Chinese medicines,which would lead to more objective,effective and accurate identification ***:Spatholobi Caulis(Jixueteng in Chinese)was used as the specimen in the development of such *** samples were microscopically examined in bright-and dark-field *** images were obtained by regular,EDF,and image stitching ***:The microscopic images of the characteristics in pulverized Jixueteng were captured,thanks to EDF imaging and image stitching techniques which allowed the detailed and full sighting of each characteristic to be obtained *** layers in anatomical transverse section,including cork,phelloderm,cortex,phloem,cambium,xylem and pith,were distinctively ***,by comparing images of bright-and dark-field microscopy,birefringent and non-birefringent components could readily be ***:With application of the developed procedure,high-definition,panoramic and microscopic images were acquired,which could be used as the reference images for microscopic identification of Chinese medicines.

关键词： extended depth of field imaging image stitching microscopic identification polarized light pharmacognosy spatholobus suberectus Dunn

Precise 3D shape measurement of three-dimensional digital image correlation for complex surfaces

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Science China(Technological Sciences) 2018年第1期61卷 68-73页

作者： YAN TianHao SU Yong ZHANG QingChuan CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern Mechanics University of Science and Technology of China

Three dimensional-digital image correlation （3D-DIC） is a widely used optical metrology in the experimental mechanics community because of its reliability, practicality, and flexibility. Although the precision of digital image correlation （DIC） has been thoroughly studied theoretically and numerically, verification experiments have seldom been performed, especially fbr complex surfaces with a small field of view （FOV）. In this work, the shape of a 1-yuan coin was measured using 3D-DIC; the shape was complex due to the presence of many fine details, and the FOV was relatively small because the coin diameter was only 25 mm. During the experiment, a novel strategy for speckle production was developed： white paint was simply sprayed onto the surface. Black paint was not used; instead, taking advantage of the reflective nature of the coin surface, polarized light and a Polaroid filter were introduced, and the polarization direction was carefully adjusted, ensuring that the spray pattern was extremely thin and that high-quality speckle images with significant contrast were captured. The three-dimensional coin shape was also successfully determined for comparison using a stylus profiler. The results demonstrate that 3D-DIC provides high precision in shape measurement even for complex surfaces with small FOV. The precision of 3D-DIC can reach 1/7000 of the field of view, corresponding to about 6 ~tm in this experiment.

关键词： three-dimensional digital image correlation(3D-DIC) measurement precision complex surfaces small field of view polarized light polaroid filter

A polarization method for quickly distinguishing the morphology of electro-spun ultrafine fibers

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Chinese Chemical Letters 2018年第8期29卷 1317-1320页

作者： Xiaopeng Li Yuanhuan Zhu Hui Ma Yong Sheng School of Materials Science and Engineering Sichuan University Center for Precision Medicine and Healthcare Tsinghua-Berkeley Shenzhen Institute Tsinghua University Shenzhen Key Laboratory for Minimal Invasive Medical Technologies Institute of Optical Imaging and Sensing Graduate School at Shenzhen Tsinghua University Department of Physics Tsinghua University

In the fields of tissue engineering and controlled drug release, electro-spun fibers are often required to have structural characteristics such as high porosity and large specific surface area. The traditional scanning electron microscope can observe the microscopic appearance of the sample clearly, but it damage to the polymer electro-spun fiber, and the detection takes a long time. In view of this, we have tested a polarization method to quickly distinguish different morphological features of the samples, such as smooth surface, microporous, and beaded microspheres using the depolarization parameter MMDD-△,which is obtained by the Mueller matrix polar decomposition. The preliminary results show that this method is simple, fast, and potentially capable of non-destructive evaluation of the microstructure properties of the object surface.

关键词： Electrospinning Ultrafine fiber polarized light Nondestructive testing Mueller matrix

The infrared transmission through gold films on ordered two-dimensional non-close-packed colloidal crystals

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Journal of Semiconductors 2014年第9期35卷 1-5页

作者：鞠晶周玉琴董刚强 University of Chinese Academy of Sciences

We studied the infrared transmission properties of gold films on ordered two-dimensional nonclose- packed polystyrene （PS） colloidal crystal. The gold films consist of gold half-shells on the PS spheres and gold film with 2D arrays of holes on the glass substrate. An extraordinary optical transmission phenomenon could be found in such a structure. Simulations with the finite-difference time-domain method were also employed to get the transmission spectra and electric field distribution. The transmission response of the samples can be adjusted by controlling the thickness of the gold films. Angle-resolved measurements were performed using polarized light to obtain more information about the surface plasmon polariton resonances of the gold films. As the angle changes, the transmission spectra change a lot. The transmission spectra of p-polarized light have quite different properties compared to those of s-polarized light.

关键词： SPP extraordinary optical transmission non-close-packed colloidal crystal polarized light

Measurement of Rotatory Optics Element in Tensor Dielectric Matrix for Rotatory Optical Fiber

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Transactions of Tianjin University 2005年第2期11卷 115-118页

作者：刘敬浩张晓帆李华舟鲍振武 School of Electronic Information Engineering Tianjin University Tianjin 300072 China

The rotatory optics element in the tensor dielectric coefficient matrix is an important para-(meter) for analyzing and calculating a rotatory optical fiber by electromagnetic theory. But the mea-(surement) of rotatory optics element is difficult for the rotatory optical fiber. A simple principle and method for measuring rotatory optics element are put forward in this paper. Firstly by using electromagnetic theory it was demonstrated that the rotatory optics element has a simple linear relation with the rotatory angle, and then the rotatory optics element has a simple linear relation with the magnetic field strength (or bias current in the helix coil) . Secondly a measurement system for the rotatory optics element in the rotatory optical fiber was designed. Using the measurement system the rotatory element can be obtained by measuring the bias current simply.

关键词： rotatory optics element tensor dielectric coefficient rotatory optic fiber polarized light

polarized Electronic Spectra of Organic/Inorganic Hybrid Materials of Chiral Schiff Base Ni（ll） or Cu（ll） Complexes and Disperse Red 1 or Azobenzene in PMMA Films

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Journal of Chemistry and Chemical Engineering 2011年第5期5卷 443-450页

作者： Takashiro Akitsu Yukie Miura Department of Chemistry Faculty of Science Tokyo University of Science Tokyo 162-8601 Japan

We have prepared new chiral Schiff base complexes, and copper（Ⅱ）（2） to investigate steric effect of ligands for 1 and bis（N-R-l-phenylethyl-5- methoxysalicydenaminato） nickel（Ⅱ）（1） 2 and known bis（N-R-l-phenylethyl-3,5-dichlorosalicydenaminato） nickel（Ⅱ）（3） and copper（Ⅱ）（4）. By using two kinds of photochromic dyes, disperse red 1 （DRI） and azobenzene （AZ）, we investigated the efficiency of increasing optical anisotropy of organic/inorganic hybrid materials of 1 through 4＋AZ or DRI＋PMMA in polymethylmethacrylate （PMMA） cast films by Weigert effect （and compared with cis-trans isomerization by alternate UV and visible light for 3 and 4 to previous study）. Gradual increase of optical anisotropy was observed for all the hybrid materials regardless of flexibility of Schiff base complexes, and the degree of dichroism and weak intermolecular interactions were discussed based on polarized absorption electronic spectra.

关键词： Photochromism chirality polarized light metal complexes Schiff base.