Journal articles: 'High light illumination'

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Shi, Fenghua, Jing Wen, and Dangyuan Lei. "High-efficiency, large-area lattice light-sheet generation by dielectric metasurfaces." Nanophotonics 9, no. 12 (June 29, 2020): 4043–51. http://dx.doi.org/10.1515/nanoph-2020-0227.

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AbstractLattice light-sheet microscopy (LLSM) was developed for long-term live-cell imaging with ultra-fine three-dimensional (3D) spatial resolution, high temporal resolution, and low photo-toxicity by illuminating the sample with a thin lattice-like light-sheet. Currently available schemes for generating thin lattice light-sheets often require complex optical designs. Meanwhile, limited by the bulky objective lens and optical components, the light throughput of existing LLSM systems is rather low. To circumvent the above problems, we utilize a dielectric metasurface of a single footprint to replace the conventional illumination modules used in the conventional LLSM and generate a lattice light-sheet with a ~3-fold broader illumination area and a significantly leveraged illumination efficiency, which consequently leads to a larger field of view with a higher temporal resolution at no extra cost of the spatial resolution. We demonstrate that the metasurface can manipulate spatial frequencies of an input laser beam in orthogonal directions independently to break the trade-off between the field of view and illumination efficiency of the lattice light-sheet. Compared to the conventional LLSM, our metasurface module serving as an ultra-compact illumination component for LLSM at an ease will potentially enable a finer spatial resolution with a larger numerical-aperture detection objective lens.

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Yoshinobu, Tatsuo, and Ko-ichiro Miyamoto. "Efficient Illumination for a Light-Addressable Potentiometric Sensor." Sensors 22, no. 12 (June 16, 2022): 4541. http://dx.doi.org/10.3390/s22124541.

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A light-addressable potentiometric sensor (LAPS) is a chemical sensor that is based on the field effect in an electrolyte–insulator–semiconductor structure. It requires modulated illumination for generating an AC photocurrent signal that responds to the activity of target ions on the sensor surface. Although high-power illumination generates a large signal, which is advantageous in terms of the signal-to-noise ratio, excess light power can also be harmful to the sample and the measurement. In this study, we tested different waveforms of modulated illuminations to find an efficient illumination for a LAPS that can enlarge the signal as much as possible for the same input light power. The results showed that a square wave with a low duty ratio was more efficient than a sine wave by a factor of about two.

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Hanji, Param, Muhammad Z. Alam, Nicola Giuliani, Hu Chen, and Rafał K. Mantiuk. "HDR4CV: High Dynamic Range Dataset with Adversarial Illumination for Testing Computer Vision Methods." Journal of Imaging Science and Technology 65, no. 4 (July 1, 2021): 40404–1. http://dx.doi.org/10.2352/j.imagingsci.technol.2021.65.4.040404.

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Abstract Benchmark datasets used for testing computer vision (CV) methods often contain little variation in illumination. The methods that perform well on these datasets have been observed to fail under challenging illumination conditions encountered in the real world, in particular, when the dynamic range of a scene is high. The authors present a new dataset for evaluating CV methods in challenging illumination conditions such as low light, high dynamic range, and glare. The main feature of the dataset is that each scene has been captured in all the adversarial illuminations. Moreover, each scene includes an additional reference condition with uniform illumination, which can be used to automatically generate labels for the tested CV methods. We demonstrate the usefulness of the dataset in a preliminary study by evaluating the performance of popular face detection, optical flow, and object detection methods under adversarial illumination conditions. We further assess whether the performance of these applications can be improved if a different transfer function is used.

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Feng, Di, Jaehwan Yoo, Kaname Nagatani, Wookyu Kim, and HyeongChae Kim. "High Illumination Efficiency Linear Light Source Using Light Emitting Diodes." Japanese Journal of Applied Physics 46, no. 2 (February 8, 2007): 563–65. http://dx.doi.org/10.1143/jjap.46.563.

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Curlin, Jahnavi, and Charles K. Herman. "Current State of Surgical Lighting." Surgery Journal 06, no. 02 (April 2020): e87-e97. http://dx.doi.org/10.1055/s-0040-1710529.

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AbstractSurgical performance in the operating room (OR) is supported by effective illumination, which mitigates the inherent environmental, operational, and visual challenges associated with surgery. Three critical components are essential to optimize operating light as illumination: (1) centering on the surgeon's immediate field, (2) illuminating a wide or narrow field with high-intensity light, and (3) penetrating into a cavity or under a flap. Furthermore, optimal surgical illumination reduces shadow, glare, and artifact in visualization of the surgical site. However, achieving these principles is more complex than at first glance, requiring a detailed examination of the variables that comprise surgical illumination. In brief, efficacious surgical illumination combines sufficient ambient light with the ability to apply focused light at specific operative stages and angles. But, brighter is not always merely better; rather, a nuanced approach, cognizant of the challenges inherent in the OR theater, can provide for a thoughtful exploration of how surgical illumination can be utilized to the best of its ability, ensuring a safe and smooth surgery for all.

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Rahman, Md Momtazur, David Luke Field, Soyed Mohiuddin Ahmed, Md Tanvir Hasan, Mohammad Khairul Basher, and Kamal Alameh. "LED Illumination for High-Quality High-Yield Crop Growth in Protected Cropping Environments." Plants 10, no. 11 (November 16, 2021): 2470. http://dx.doi.org/10.3390/plants10112470.

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Vegetables and herbs play a central role in the human diet due to their low fat and calory content and essential antioxidant, phytochemicals, and fiber. It is well known that the manipulation of light wavelengths illuminating the crops can enhance their growth rate and nutrient contents. To date, it has not been easy to generalize the effects of LED illumination because of the differences in the plant species investigated, the measured traits, the way wavelengths have been manipulated, and the plants’ growing environments. In order to address this gap, we undertook a quantitative review of LED manipulation in relation to plant traits, focusing on vegetables and herbs. Here, we use standardized measurements of biomass, antioxidant, and other quantitative characteristics together with the whole range of the photosynthetic photon flux density (PPFD). Overall, our review revealed support for the claims that the red and blue LED illumination is more reliable and efficient than full spectrum illumination and increases the plant’s biomass and nutritional value by enhancing the photosynthetic activity, antioxidant properties, phenolic, and flavonoids contents. Although LED illumination provides an efficient way to improve yield and modify plant properties, this study also highlights the broad range of responses among species, varieties traits, and the age of plant material.

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Wang, Depeng, Suva Roy, Andra M. Rudzite, Greg D. Field, and Yiyang Gong. "High-resolution light-field microscopy with patterned illumination." Biomedical Optics Express 12, no. 7 (June 8, 2021): 3887. http://dx.doi.org/10.1364/boe.425742.

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Shao, Wei, Kaibin Liu, Yunqiu Shao, and Awei Zhou. "Smooth Surface Visual Imaging Method for Eliminating High Reflection Disturbance." Sensors 19, no. 22 (November 14, 2019): 4953. http://dx.doi.org/10.3390/s19224953.

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At present, visual imaging is widely applied for surface defects such as bumps and scratches in the manufacture of precise parts with a highly reflective surface. However, the high light reflection and halo disturbance as a result of the illumination in visual imaging exert a direct influence on the accuracy of defect detection. In this regard, the present paper develops an adaptive illumination method based on space–time modulation for a visual imaging system. Furthermore, a digital micro-mirror device (DMD) is employed to realize the pixel-level spatiotemporal modulation of illumination. Then, in combination with the illumination intensity feedback of charge coupled device (CCD), the time-space ratio is adjusted automatically to achieve adaptive uniform illumination and effectively suppress the high light reflection and halo disturbance of highly reflective surfaces. The experimental results show that, in terms of restraining high light disturbance, the visibility and accuracy of visual imaging are improved.

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Ito, Yuhei, Kyouichi Suzuki, Tsuyoshi Ichikawa, Yoichi Watanabe, Taku Sato, Jun Sakuma, and Kiyoshi Saito. "Intraoperative Fluorescence Cerebral Angiography by Laser Surgical Microscopy: Comparison With Xenon Microscopy and Simultaneous Observation of Cerebral Blood Flow and Surrounding Structures." Operative Neurosurgery 16, no. 6 (June 12, 2018): 700–706. http://dx.doi.org/10.1093/ons/opy159.

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Abstract BACKGROUND Laser surgical microscopes should enable uniform illumination of the operative field, and require less luminous energy compared with existing xenon surgical microscopes. OBJECTIVE To examine the utility of laser illumination in fluorescence cerebral angiography. METHODS Fluorescein sodium (fluorescein) was used as a fluorescent dye. We first compared the clarity of cerebral blood flow images collected by fluorescence angiography between the laser illumination and xenon illumination methods. We then assessed use of the laser illuminator for simultaneous observation of blood flow and surrounding structures during fluorescence angiography. Furthermore, the study was designed to evaluate usefulness of the thus determined excitation light in clinical cases. RESULTS Fluorescence angiography using blue light laser for excitation provided higher clarity and contrast blood flow images compared with using blue light generated from a xenon lamp. Further, illumination with excitation light consisting of a combination of 3 types of laser (higher level of blue light, no green light, and lower level of red light) enabled both blood flow and surrounding structures to be observed through the microscope directly by the surgeon. CONCLUSION Laser-illuminated fluorescence angiography provides high clarity and contrast images of cerebral blood flow. Further, a laser providing strong blue light and weak red light for excitation light enables simultaneous visual observation of fluorescent blood flow and surrounding structures by the surgeon using a surgical microscope. Overall, these data suggest that laser surgical microscopes are useful for both ordinary operative manipulations and fluorescence angiography.

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Yabuuchi, Kento, Masahiro Hirano, Taku Senoo, Norimasa Kishi, and Masatoshi Ishikawa. "Real-Time Traffic Light Detection with Frequency Patterns Using a High-Speed Camera." Sensors 20, no. 14 (July 20, 2020): 4035. http://dx.doi.org/10.3390/s20144035.

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LEDs are widely employed as traffic lights. Because most LED traffic lights are driven by alternative power, they blink at high frequencies, even at twice their frequencies. We propose a method to detect a traffic light from images captured by a high-speed camera that can recognize a blinking traffic light. This technique is robust under various illuminations because it can detect traffic lights by extracting information from the blinking pixels at a specific frequency. The method is composed of six modules, which includes a band-pass filter and a Kalman filter. All the modules run simultaneously to achieve real-time processing and can run at 500 fps for images with a resolution of 800 × 600. This technique was verified on an original dataset captured by a high-speed camera under different illumination conditions such as a sunset or night scene. The recall and accuracy justify the generalization of the proposed detection system. In particular, it can detect traffic lights with a different appearance without tuning parameters and without datasets having to be learned.

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Rustemli, Sabir, Behcet Kocaman, and Suat Avcil. "Comparative Analysis of High-Pressure Sodium Vapor Luminaires with LED Luminaires in Tunnel Illumination." Light & Engineering, no. 04-2022 (August 2022): 87–96. http://dx.doi.org/10.33383/2022-003.

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Nowadays, some roads pass through underground tunnels due to technical inadequacy and high economic costs in constructing highways, railways, and pedestrians. Tunnels are opened to pass through obstacles on the route (mountain, hill, etc.) to force the driver, disturb him, reduce the ramps that could endanger safety depending on nature’s state, and shorten travel distances. In this way, number of tunnels along with the road increases, and illuminating these tunnels with different characteristics varies day and night. Tunnel illumination calculations and applications are essential as good tunnel illumination ensures the same flow of comfort, speed, and safety as on the approaching road. Moreover, with the advancement of tunnel technology, many types of equipment are used inside and outside the tunnel, and electricity needs vary according to these types of equipment. In this research, the importance of tunnel illumination was discussed and comparative illumination analysis in 8 August tunnel in Bitlis was conducted. Illumination for the Bitlis 8 August tunnel was done using luminaires with high-pressure sodium vapor lamps, and the grid was used to generate all the energy required. In this study, the energy used by the Bitlis 8 August tunnel for illumination was obtained from the accurate data and the results were compared with the initial situation when the same system was installed using light emitting diode (LED) illumination technology.

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Leng, Xue, and Jin Hua Yang. "Light Illumination Information Extraction Method of High Dynamic Range Image." Advanced Materials Research 756-759 (September 2013): 952–55. http://dx.doi.org/10.4028/www.scientific.net/amr.756-759.952.

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In this Paper we Investigated Access Technology of the Light Illumination Information in Real Scene. by Analyzing the Conventional Method, we Proposed a Method to Access Light Illumination Information of High Dynamic Range Image. in the Method, the Image Information Obtained by Camera was Converted to the Panoramic Image by Using Image Mosaic Technology and then Converted to the High Dynamic Range Image by the Software HDR.

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Azis, Abdul, Nita Nurdiana, and Choirul Rizal. "Illumination Analysis Patal Pusri Intersection Underground Road." Jurnal Tekno 19, no. 2 (October 26, 2022): 1–10. http://dx.doi.org/10.33557/jtekno.v19i2.1676.

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The traffic lane underpass is shaped tunnels built to provide a solution to traffic congestion that occurred on an, intersections and long underpass usually less than 0,1. 0,16 miles or miles Underpass Simpang Patal Pusri Palembang is a reserved for public, traffic and the public must be furnished with equipage. Road one way is the street lights, for that reason by Underpass Simpang Patal Pusri Palembang has installed lights. public roadsA kind of light to overpass, flat, intersection the sodium light the gas is high pressure or high-pressure sodium, son with the normal lighting 20 - 25 lux and efficiency of the average 110 lumen/ watts with a view to provide comfort and safety for road users. This study aims to to know the intensity of light lighting, the intensity of lighting and analyze the worthiness of the lighting on the street lights Underpass Simpang Patal Pusri Palembang. The research the results in the light of that flux SON-T 200 22.000 lumen. to wattsSome of the results of the intensity of the light in the Underpass Patal Pusri intersection of Palembang 668,7395 candela influenced by factors settings 0,65 as much as percent. The intensity of the light/illumination highest located at the T1 worth E = 30,56 lux influenced by the L1 - L12 until. To their intensity light/illumination highest located at the lowest point of the L2 = E 14,69 lux who influenced by the L1 - L12 until. Standard for lighting a street underpass sni 7391: 2008 to 20 lux until 25, lux so the lighting is Underpass Simpang Patal Pusri Palembang still in accordance with standard value determined by sni 7391: 2008 which is 20-25. lux The results of which of ERate of 23,39. lux.

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Hao, R., A. Ge, X. Tao, Y. Liu, B. Zhao, and E. Yang. "Optical design of a high-mast luminaire based on four COB LED light source modules." Lighting Research & Technology 51, no. 3 (May 14, 2018): 447–56. http://dx.doi.org/10.1177/1477153518764774.

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Light-emitting diodes (LEDs) have been widely used in road lighting. This study investigates the optical design of a high-mast luminaire based on four chips-on-board LED light source modules and applies it to road lighting. The model of the high-mast luminaire is built with Solidworks, and then the optical simulations are analysed by Tracepro and Dialux. We also make a physical prototype of the high-mast luminaire to test its performance in practice. The illuminance distribution of the test area is nearly rectangular. The interior of the rectangle forms a smaller highlighted rectangular illumination area with uniform illumination. The outer edges of the rectangular illumination area will overlap the outer edges of the illumination area of other high-mast luminaires. The desired illuminance distribution and the uniform illumination can be obtained. Both the simulations and the experimental results meet the requirements of road lighting standards and the high-mast lamp can even achieve a better optical performance.

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Lapa, Havva Elif, Ali Kökce, Durmuş Ali Aldemir, and Ahmet Faruk Özdemir. "The response of high barrier Schottky diodes to light illumination." Journal of Materials Science: Materials in Electronics 32, no. 4 (January 15, 2021): 4448–56. http://dx.doi.org/10.1007/s10854-020-05186-6.

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Lee, Chi-Yuan, and Jian-Lin Liu. "Illumination Based on High-Power White Light-Emitting Diode Array." International Journal of Green Energy 9, no. 5 (July 2012): 421–29. http://dx.doi.org/10.1080/15435075.2011.621489.

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Journal, Baghdad Science. "The contrast and illumination technique for image capturing under different Tungsten illumination." Baghdad Science Journal 7, no. 2 (June 6, 2010): 939–47. http://dx.doi.org/10.21123/bsj.7.2.939-947.

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The digital camera which contain light unit inside it is useful with low illumination but not for high. For different intensity; the quality of the image will not stay good but it will have dark or low intensity so we can not change the contrast and the intensity in order to increase the losses information in the bright and the dark regions. . In this search we study the regular illumination on the images using the tungsten light by changing the intensities. The result appears that the tungsten light gives nearly far intensity for the three color bands(RGB) and the illuminated band(L).the result depend on the statistical properties which represented by the voltage ,power and intensities and the effect of this parameter on the digital camera .

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Rolston, Nicholas, Ross Bennett-Kennett, Laura T. Schelhas, Joseph M. Luther, Jeffrey A. Christians, Joseph J. Berry, and Reinhold H. Dauskardt. "Comment on “Light-induced lattice expansion leads to high-efficiency perovskite solar cells”." Science 368, no. 6488 (April 16, 2020): eaay8691. http://dx.doi.org/10.1126/science.aay8691.

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Tsai et al. (Reports, 6 April 2018, p. 67) report a uniform light-induced lattice expansion of metal halide perovskite films under 1-sun illumination and claim to exclude heat-induced lattice expansion. We show that by controlling the temperature of the perovskite film under both dark and illuminated conditions, the mechanism for lattice expansion is in fact fully consistent with heat-induced thermal expansion during illumination.

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Száz, Dénes, Zoltán Kolláth, Ferenc Szabó, and Péter Csuti. "Living Environmental Laboratory for Lighting: Reduction of Light Pollution at Hungarian Settlements." International Journal of Sustainable Lighting 21, no. 2 (July 9, 2020): 66–75. http://dx.doi.org/10.26607/ijsl.v21i2.90.

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The International Dark Sky Association has a flight of rules for public lighting in dark sky parks. In Hungary, many settlements still illuminate with compact fluorescent lights and sodium lamps, that do not fulfill these rules. In our research project, financed by a grant of the European Union, we established a system of Living Environmental Laboratory for Lighting at two settlements in dark sky parks in Hungary. As the first step, the public lighting system was reconstructed, so that it satisfied the rules of IDA. We designed new LED luminaires with optimal illumination and optical properties to provide the necessary luminous intensity and reduce light pollution at the same time. The new system has a two-step illumination profile: (i) Early night, after sunset, when the traffic is still high, warm white LEDs are applied to ensure sufficient lighting coming to the roads and pavements with a wide beam of light. (ii) Late night, when the traffic is low, the illumination switches to amber LEDs that have a narrower light beam to minimize light pollution and provide sufficient visibility. This approach can be an optimal illumination construction to reduce the light pollution of public lighting at night.

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Keomanee-Dizon, Kevin, Matt Jones, Peter Luu, Scott E. Fraser, and Thai V. Truong. "Extended depth-of-field light-sheet microscopy improves imaging of large volumes at high numerical aperture." Applied Physics Letters 121, no. 16 (October 17, 2022): 163701. http://dx.doi.org/10.1063/5.0101426.

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Light-sheet microscopes must compromise among field of view, optical sectioning, resolution, and detection efficiency. High-numerical-aperture (NA) detection objective lenses provide higher resolution, but their narrow depth of field inefficiently captures the fluorescence signal generated throughout the thickness of the illumination light sheet when imaging large volumes. Here, we present ExD-SPIM (extended depth-of-field selective-plane illumination microscopy), an improved light-sheet microscopy strategy that solves this limitation by extending the depth of field (DOF) of high-NA detection objectives to match the thickness of the illumination light sheet. This extension of the DOF uses a phase mask to axially stretch the point-spread function of the objective lens while largely preserving lateral resolution. This matching of the detection DOF to the illumination-sheet thickness increases the total fluorescence collection, reduces the background, and improves the overall signal-to-noise ratio (SNR), as shown by numerical simulations, imaging of bead phantoms, and imaging living animals. In comparison to conventional light sheet imaging with low-NA detection that yields equivalent DOF, the results show that ExD-SPIM increases the SNR by more than threefold and dramatically reduces the rate of photobleaching. Compared to conventional high-NA detection, ExD-SPIM improves the signal sensitivity and volumetric coverage of whole-brain activity imaging, increasing the number of detected neurons by over a third.

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Steude, Anja, Emily C. Witts, Gareth B. Miles, and Malte C. Gather. "Arrays of microscopic organic LEDs for high-resolution optogenetics." Science Advances 2, no. 5 (May 2016): e1600061. http://dx.doi.org/10.1126/sciadv.1600061.

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Optogenetics is a paradigm-changing new method to study and manipulate the behavior of cells with light. Following major advances of the used genetic constructs over the last decade, the light sources required for optogenetic control are now receiving increased attention. We report a novel optogenetic illumination platform based on high-density arrays of microscopic organic light-emitting diodes (OLEDs). Because of the small dimensions of each array element (6 × 9 μm2) and the use of ultrathin device encapsulation, these arrays enable illumination of cells with unprecedented spatiotemporal resolution. We show that adherent eukaryotic cells readily proliferate on these arrays, and we demonstrate specific light-induced control of the ionic current across the membrane of individual live cells expressing different optogenetic constructs. Our work paves the way for the use of OLEDs for cell-specific optogenetic control in cultured neuronal networks and for acute brain slices, or as implants in vivo.

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Long, Teng, Xingqiang Dai, Linfeng Lan, Caihao Deng, Zhuo Chen, Changchun He, Lu Liu, Xiaobao Yang, and Junbiao Peng. "High-performance CdScInO thin-film transistors and their stability improvement under negative bias (illumination) temperature stress." Journal of Materials Chemistry C 7, no. 44 (2019): 13960–65. http://dx.doi.org/10.1039/c9tc04989d.

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Ding, Zicheng, Ruyan Zhao, Yingjian Yu, and Jun Liu. "All-polymer indoor photovoltaics with high open-circuit voltage." Journal of Materials Chemistry A 7, no. 46 (2019): 26533–39. http://dx.doi.org/10.1039/c9ta10040g.

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Różowicz, Antoni, Henryk Wachta, Krzysztof Baran, Marcin Leśko, and Sebastian Różowicz. "Arrangement of LEDs and Their Impact on Thermal Operating Conditions in High-Power Luminaires." Energies 15, no. 21 (November 1, 2022): 8142. http://dx.doi.org/10.3390/en15218142.

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Solid-state light sources are currently the fastest-growing group of light sources, replacing the previously used discharge and incandescent light sources. Thermal operating conditions of LEDs (Light Emitting Diode) play an important role in t maintaining long service life and constancy of luminous-electrical parameters. In the field of illumination, the service life parameter of light sources is important for the costs of maintenance of the illumination system, while the maintenance of the value of certain light parameters over time, such as luminous flux, color temperature and color rendering index, is related to the aesthetic effect of the illumination. In addition, limiting the junction temperature of solid-state light sources is particularly important in high-power luminaires dedicated to flood illumination. One of the elements shaping the thermal operating conditions of multi-source LED luminaires is the number of luminaires used, their arrangement, and the distance between LEDs installed on the MCPCB (Metal Core Printed Circuit Board) substrate. This article presents the results of simulation studies, realized using CFD (Computational Fluid Dynamics) software, where the temperature distribution and the junction temperature of the LED panel were determined for different configurations and distances between the LEDs. The results obtained were analyzed and conclusions were drawn based on them. Thermal tests performed and presented in the article cover scientific issues related to shaping the temperature distribution of the LED panel. They make it possible to determine the influence of thermal couplings between the sources, related to their number, distance and the value of the forward current, on the final temperature of the LED junction temperature. The presented research results may constitute auxiliary materials for designers of lighting luminaires, especially high-power luminaires, where a large number of high-power LED sources are installed in close proximity.

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RUCHIN, Alexander B. "EFFECT OF ILLUMINATION ON GROWTH AND BEHAVIOR OF TWO CARP FISH SPECIES (CARASSIUS GIBELIO AND C. CARASSIUS)." Periódico Tchê Química 16, no. 32 (August 20, 2019): 8–17. http://dx.doi.org/10.52571/ptq.v16.n32.2019.26_periodico32_pgs_8_17.pdf.

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Light is one of the most important environmental factors that influence many physiological, biochemical and behavioral reactions of aquatic organisms. In this work, experiments were conducted to study how illumination influences on the growth of juveniles of two carp fish species (Carassius gibelio and Carassius carassius). In this work, experiments. The experiments were carried out in aquariums and trays with a light gradient. Twenty-twenty five fish were placed in each aquarium, three-four individuals were placed in trays. Fish were fed to saturation three times a day. Optimal types of illumination were identified for the growth of both species. 200–930 lx is optimal for juvenile Carassius gibelio. 230–500 lx is optimal for juvenile Carassius carassius. High illumination and total darkness negatively influenced the growth of both species. Very high illumination considerably slowed the growth rate. Survival in all cases was at 100%. Motor activity of juvenile Carassius gibelio in light-gradient conditions was higher than in balancing illumination. The number of vector movements, the average distance of movement and the total path of fish in the light gradient exceed the corresponding values in control in balancing illumination. When there was no food, the elected zones of the juvenile Carassius gibelio were shifted toward higher illumination. When the food was absent for half an hour, the juveniles chose a zone with the illumination of 600 lux (total time of stay was 15.8 minutes for 1 h). When it was absent for two hours, the juveniles chose a zone with the illumination of 1000 lux (17.3 minutes), and when it was absent for 24 hours, juveniles chose a zone with the illumination of 1000–1200 lux (28.5 minutes). The study discusses the effect of light on growth, the behavior of two species of fish.

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Hell, Stefan W., Pekka E. Hanninen, Martin Schrader, Tony Wilson, and Erkki Soini. "Resolution beyond the diffraction limit: 4PI-confocal-, STED-, and GSD- fluorescence microscopy." Proceedings, annual meeting, Electron Microscopy Society of America 53 (August 13, 1995): 56–57. http://dx.doi.org/10.1017/s0424820100136659.

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In far-field light microscopy resolution is determined by diffraction. In a far-field light microscope such as the confocal scanning light microscope, the resolution is governed by the extent of the squared intensity distribution in the focal region. Precise measurements of the confocal PSF have shown that the axial and lateral resolution of a confocal microscope (NA=1.4 oil, 1= 633 nm) is 520nm and 200nm (FWHM), respectively. At a wavelength of 375nm, this amounts to a resolution of 300 nm (axial) and 120 nm (lateral), obtainable with a standard confocal microscope of high aperture.A 3-7 fold increase in axial resolution is achieved with a 4Pi-confocal microscope. The 4Piconfocal microscope uses two high numerical aperture objective lenses that are used coherently for illuminating or detecting the same point in the object space. The present paper deals with the latest developments in the field of 4Pi-confocal microscopy. The Optical Transfer Functions (OTF) of 4Piconfocal microscopies with 4Pi-illumination (type A), 4Pi-detection (type B), and 4Pi illumination and detection (type C) are measured and compared with their standard confocal counterpart.

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Serôdio, João, William Schmidt, Jörg C. Frommlet, Gregor Christa, and Matthew R. Nitschke. "An LED-based multi-actinic illumination system for the high throughput study of photosynthetic light responses." PeerJ 6 (September 4, 2018): e5589. http://dx.doi.org/10.7717/peerj.5589.

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The responses of photosynthetic organisms to light stress are of interest for both fundamental and applied research. Functional traits related to the photoinhibition, the light-induced loss of photosynthetic efficiency, are particularly interesting as this process is a key limiting factor of photosynthetic productivity in algae and plants. The quantitative characterization of light responses is often time-consuming and calls for cost-effective high throughput approaches that enable the fast screening of multiple samples. Here we present a novel illumination system based on the concept of ‘multi-actinic imaging’ of in vivo chlorophyll fluorescence. The system is based on the combination of an array of individually addressable low power RGBW LEDs and custom-designed well plates, allowing for the independent illumination of 64 samples through the digital manipulation of both exposure duration and light intensity. The illumination system is inexpensive and easily fabricated, based on open source electronics, off-the-shelf components, and 3D-printed parts, and is optimized for imaging of chlorophyll fluorescence. The high-throughput potential of the system is illustrated by assessing the functional diversity in light responses of marine macroalgal species, through the fast and simultaneous determination of kinetic parameters characterizing the response to light stress of multiple samples. Although the presented illumination system was primarily designed for the measurement of phenotypic traits related to photosynthetic activity and photoinhibition, it can be potentially used for a number of alternative applications, including the measurement of chloroplast phototaxis and action spectra, or as the basis for microphotobioreactors.

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Madrid-Wolff, Jorge, and Manu Forero-Shelton. "Protocol for the Design and Assembly of a Light Sheet Light Field Microscope." Methods and Protocols 2, no. 3 (July 4, 2019): 56. http://dx.doi.org/10.3390/mps2030056.

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Light field microscopy is a recent development that makes it possible to obtain images of volumes with a single camera exposure, enabling studies of fast processes such as neural activity in zebrafish brains at high temporal resolution, at the expense of spatial resolution. Light sheet microscopy is also a recent method that reduces illumination intensity while increasing the signal-to-noise ratio with respect to confocal microscopes. While faster and gentler to samples than confocals for a similar resolution, light sheet microscopy is still slower than light field microscopy since it must collect volume slices sequentially. Nonetheless, the combination of the two methods, i.e., light field microscopes that have light sheet illumination, can help to improve the signal-to-noise ratio of light field microscopes and potentially improve their resolution. Building these microscopes requires much expertise, and the resources for doing so are limited. Here, we present a protocol to build a light field microscope with light sheet illumination. This protocol is also useful to build a light sheet microscope.

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Clarke, Ted. "Resolving Low-Contrast Microstructure Using Transmitted and Reflected Circular Oblique Lighting (COL)." Microscopy Today 20, no. 3 (May 2012): 38–41. http://dx.doi.org/10.1017/s1551929511000642.

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A little-known illumination method for light microscopy goes by several names, the most prominent being “circular oblique lighting” (COL) and “hollow-cone illumination”. Matthews notes that hollow-cone or annular bright field illumination can give contrast and resolution superior to that obtainable with narrow-pencil illumination and under favorable conditions comparable to that obtained with phase optics. He demonstrates this with photomicrographs of the same unstained epithelial cell from the mouth mounted in saliva, imaged with a 0.65 numerical aperture (NA) 40× objective. Matthews also notes that the dot pattern of Pleurosigmaangulatum can be resolved with a 0.50 NA objective using circular oblique lighting. Leitz previously marketed the Heine illuminator for transmitted annular (hollow cone) illumination. The NA of the Heine condenser's annular illumination can be adjusted to match the phase annuli in phase contrast objectives. The NA can be increased to provide dark field illumination or circular oblique illumination in bright field. The instructions for the Heine condenser call for the annular illumination just falling within the NA of the objective, what Paul James calls COL and Frithjof A. S. Sterrenberg calls extreme annular illumination, “bright field with very rich contrast.” H. J. Dethloff published a more recent article describing the need for the increased contrast of hollow cone bright field to help resolve the striae of pores in the diatom Amplipleurapellucida. This diatom has been the traditional test of the resolution limit of the light microscope; it is considered a low-contrast subject because the visibility of pores in the transparent amorphous silica frustules is determined by the refractive index difference between the mountant and the frustules. The low contrast makes this a challenging, perhaps even unsuitable, test object for resolution. Resolution tests of modern objectives are done with high-contrast but costly patterns of chrome on glass obtained by electron lithography.

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Cannell, M. B., and C. Soeller. "High Resolution Imaging Using Confocal and 2-photon Molecular Excitation Microscopy." Microscopy Today 8, no. 5 (June 2000): 20–26. http://dx.doi.org/10.1017/s1551929500065196.

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Fluorescence microscopy has proved to be an invaluable tool for biomedical science since it is possible to visualise small quantities of labelled materials (such as intracellular ions and proteins) in both fixed and living cells. However, the conventional wide field fluorescence microscope suffers from the disadvantage that objects outside the focal plane also fluoresce (in response to the excitation light) and this leads to a marked loss of contrast for objects in the focal plane. This is especially a problem when the fluorescent probe is distributed throughout the thickness of the cell and the cell is thicker than about 1 μm. The confocal microscope overcomes this problem by illuminating the preparation with a point source of excitation light and limiting the collection of light with a pinhole that is confocal with the illumination source. This converts the microscope from an imaging system to a point detector and images are produced by scanning the illuminating and detecting point over the specimen to build an image (in much the same way that a television set produces an image). The basic idea behind the confocal system is shown in Figure 1, and it should be noted that light from points outside the focal plane is defocused at the pinhole and so does not pass through the pinhole efficiently.

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Tsai, Hsinhan, Reza Asadpour, Jean-Christophe Blancon, Constantinos C. Stoumpos, Olivier Durand, Joseph W. Strzalka, Bo Chen, et al. "Light-induced lattice expansion leads to high-efficiency perovskite solar cells." Science 360, no. 6384 (April 5, 2018): 67–70. http://dx.doi.org/10.1126/science.aap8671.

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Light-induced structural dynamics plays a vital role in the physical properties, device performance, and stability of hybrid perovskite–based optoelectronic devices. We report that continuous light illumination leads to a uniform lattice expansion in hybrid perovskite thin films, which is critical for obtaining high-efficiency photovoltaic devices. Correlated, in situ structural and device characterizations reveal that light-induced lattice expansion benefits the performances of a mixed-cation pure-halide planar device, boosting the power conversion efficiency from 18.5 to 20.5%. The lattice expansion leads to the relaxation of local lattice strain, which lowers the energetic barriers at the perovskite-contact interfaces, thus improving the open circuit voltage and fill factor. The light-induced lattice expansion did not compromise the stability of these high-efficiency photovoltaic devices under continuous operation at full-spectrum 1-sun (100 milliwatts per square centimeter) illumination for more than 1500 hours.

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Heine, Jörn, Matthias Reuss, Benjamin Harke, Elisa D’Este, Steffen J. Sahl, and Stefan W. Hell. "Adaptive-illumination STED nanoscopy." Proceedings of the National Academy of Sciences 114, no. 37 (August 28, 2017): 9797–802. http://dx.doi.org/10.1073/pnas.1708304114.

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The concepts called STED/RESOLFT superresolve features by a light-driven transfer of closely packed molecules between two different states, typically a nonfluorescent “off” state and a fluorescent “on” state at well-defined coordinates on subdiffraction scales. For this, the applied light intensity must be sufficient to guarantee the state difference for molecules spaced at the resolution sought. Relatively high intensities have therefore been applied throughout the imaging to obtain the highest resolutions. At regions where features are far enough apart that molecules could be separated with lower intensity, the excess intensity just adds to photobleaching. Here, we introduce DyMIN (standing for Dynamic Intensity Minimum) scanning, generalizing and expanding on earlier concepts of RESCue and MINFIELD to reduce sample exposure. The principle of DyMIN is that it only uses as much on/off-switching light as needed to image at the desired resolution. Fluorescence can be recorded at those positions where fluorophores are found within a subresolution neighborhood. By tuning the intensity (and thus resolution) during the acquisition of each pixel/voxel, we match the size of this neighborhood to the structures being imaged. DyMIN is shown to lower the dose of STED light on the scanned region up to ∼20-fold under common biological imaging conditions, and >100-fold for sparser 2D and 3D samples. The bleaching reduction can be converted into accordingly brighter images at <30-nm resolution.

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Lacroix, Christian R., and Judith MacIntyre. "New techniques and applications for epi-illumination light microscopy." Canadian Journal of Botany 73, no. 11 (November 1, 1995): 1842–47. http://dx.doi.org/10.1139/b95-196.

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This modification to the technique of epi-illumination light microscopy makes use of a new system of lenses that replaces expensive and not readily available dipping cone objectives. The newer objectives offer at least comparable resolution and depth of field, along with simple preparation procedures. An epi-illumination system is a good intermediate between the stereo microscope and a scanning electron microscope, offering magnification at high power that can aid in evaluation of potential scanning electron microscope specimens, as well as the time- and material-saving feature of being able to eliminate unsuitable scanning electron microscope specimens. Key words: technique, epi-illumination, morphogenesis, vegetative apex, primordium, staining.

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Ayoub, Ahmed B., Abhijit Roy, and Demetri Psaltis. "Optical Diffraction Tomography Using Nearly In-Line Holography with a Broadband LED Source." Applied Sciences 12, no. 3 (January 18, 2022): 951. http://dx.doi.org/10.3390/app12030951.

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We present optical tomography methods for a 3D refractive index reconstruction of weakly scattering objects using LED light sources. We are able to record holograms by minimizing the optical path difference between the signal and reference beams while separating the scattered field from its twin image. We recorded multiple holograms by illuminating the LEDs sequentially and reconstructed the 3D refractive index reconstruction of the sample. The reconstructions show high signal-to-noise ratio in which the effect of speckle artifacts is highly minimized due to the partially incoherent illumination of the LEDs. Results from combining different illumination wavelengths are also described demonstrating higher acquisition speed.

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Liu, Yu, Hong Tao Miao, Min Huang, Ai Ping Liu, and Xian Yao Wu. "Research on Visual Performance under Different Lighting Environments of LED Light Sources." Applied Mechanics and Materials 731 (January 2015): 92–96. http://dx.doi.org/10.4028/www.scientific.net/amm.731.92.

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In order to study the LED light source illumination and the correlated color temperature effect on the human eye visual performance and physiological changes, through the comparative experiments of visual task performances under the different color temperature (3000K low color temperature, 4000K intermediate color temperature) and the different illumination (1145lux high intensity, 500lux middle intensity, 288lux low illumination), study the relationship between the biological effect and visual performance from two aspects of the visual perception performance and the physical efficiency such as blood pressure and pulse. Research indicates that color temperature 3000K or 4000K, intensity of illumination in about 500lux LED light source is suitable to visual task.

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Li, Yang, Marvin Knöchelmann, and Roland Lachmayer. "Beam Pre-Shaping Methods Using Lenslet Arrays for Area-Based High-Resolution Vehicle Headlamp Systems." Applied Sciences 10, no. 13 (July 1, 2020): 4569. http://dx.doi.org/10.3390/app10134569.

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High-resolution light distributions are lately in demand for vehicle headlamp systems as an innovative lighting approach. This lighting approach can realize functionalities, such as precise glare avoidance and on-road projection, which are useful for improving traffic comfort and safety. For achieving the required high-resolution light distribution, area-based projection technologies, such as DMD, LCD, and LCoS, are considered to be integrated into such headlamps. These projection devices demand rectangular illumination areas with specific light distributions to fulfill the requirements for illumination efficiency and performance in headlamp systems. Lenslet arrays, based on the principle of Köhler illumination, can effectively homogenize the light and shape it into rectangular shapes simultaneously. Such components are widely used in projection applications. However, they also show functional potentialities to be applied in high-resolution headlamps. This paper explains the design principles and methods of lenslet arrays for beam pre-shaping in headlamp systems. It validates the homogenization using a self-designed and manufactured lenslet array in a demonstrator in the first place. Afterward, this paper introduces two new methods for the centralized beam shaping required by some headlamps. These methods are validated by optical simulations.

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Yang, Xiu Zeng. "FPGA-Based High Precision Illumination Measurement System: A Prototype Development and Evaluation." Applied Mechanics and Materials 599-601 (August 2014): 944–47. http://dx.doi.org/10.4028/www.scientific.net/amm.599-601.944.

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The light is a most important natural resource for human to survive .Aiming at the shortcomings of the traditional light intensity measuring instrument ,a kind of high resolution illumination measurement system based on FPGA is designed ,which consists of special BH1750 light sensors and programmable logic gate array (FPGA) . A soft core Nios II is used as controller in the instrument, and BH1750 is put into use to acquire light signal .The testing results show that the design is feasible.

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Guo, Tianyi, Anastasiia Svanidze, Xiaoyu Zheng, and Peter Palffy-Muhoray. "Regimes in the Response of Photomechanical Materials." Applied Sciences 12, no. 15 (July 31, 2022): 7723. http://dx.doi.org/10.3390/app12157723.

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Photomechanical materials perform mechanical work in response to illumination. Photoisomerization-based photomechanical materials may operate in different regimes depending on the intensity of the illuminating light. We examine the photoresponse of liquid crystalline azo-acrylate networks and show that a material property, the characteristic intensity of the material, defines the boundaries between different regimes. Asymptotic analysis indicates that whereas at low relative light levels, photostress is proportional to intensity, at high levels, it is proportional to fluence. Model predictions are in good agreement with the experimental results.

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JIANG Xin-yu, 姜昕宇, 文尚胜 WEN Shang-sheng, 马丙戌 MA Bing-xu, 卢允乐 LU Yun-le, and 蔡明兴 CAI Ming-xing. "Design of High Illumination Uniformity Inverted LED Plant Light Source System." Chinese Journal of Luminescence 40, no. 9 (2019): 1172–84. http://dx.doi.org/10.3788/fgxb20194009.1172.

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JIANG Xin-yu, 姜昕宇, 文尚胜 WEN Shang-sheng, 左. 欣. ZUO Xin, 马丙戌 MA Bing-xu, 靳肖林 JIN Xiao-lin, 蔡明兴 CAI Ming-xing, 陈妍如 CHEN Yan-ru, 焦飞宇 JIAO Fei-yu, 张. 博. ZHANG Bo, and 吴启保 WU Qi-bao. "High Illumination Uniformity Inverted Plant Light Source Design with Bulge Structure." Chinese Journal of Luminescence 41, no. 3 (2020): 339–49. http://dx.doi.org/10.3788/fgxb20204103.0339.

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Itoh, Ryosuke, Joseph Russell Landry, Stephen Sanborn Hamann, and Olav Solgaard. "Light sheet fluorescence microscopy using high-speed structured and pivoting illumination." Optics Letters 41, no. 21 (October 26, 2016): 5015. http://dx.doi.org/10.1364/ol.41.005015.

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Harbers, Gerard, Serge J. Bierhuizen, and Michael R. Krames. "Performance of High Power Light Emitting Diodes in Display Illumination Applications." Journal of Display Technology 3, no. 2 (June 2007): 98–109. http://dx.doi.org/10.1109/jdt.2007.894384.

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ARISTOV, Y. "High-density conversion of light energy via direct illumination of catalyst." International Journal of Hydrogen Energy 22, no. 9 (September 1997): 869–74. http://dx.doi.org/10.1016/s0360-3199(96)00238-8.

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Whang, Allen Jong-Woei, Yi-Yung Chen, Tsai-hsien Yang, Yi-Lin Lin, Wei-Chieh Tseng, and Hsi-Chi Chen. "High-efficiency confocal paraboloids coupler design for natural light illumination systems." Solar Energy 195 (January 2020): 129–37. http://dx.doi.org/10.1016/j.solener.2019.11.059.

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Chang, Chong-Min, and Han-Ping D. Shieh. "High-Efficiency Polarized Light Illumination System for Liquid-Crystal-Display Projectors." Japanese Journal of Applied Physics 39, Part 1, No. 12A (December 15, 2000): 6580–81. http://dx.doi.org/10.1143/jjap.39.6580.

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Fadero, Tanner C., Therese M. Gerbich, Kishan Rana, Aussie Suzuki, Matthew DiSalvo, Kristina N. Schaefer, Jennifer K. Heppert, et al. "LITE microscopy: Tilted light-sheet excitation of model organisms offers high resolution and low photobleaching." Journal of Cell Biology 217, no. 5 (February 28, 2018): 1869–82. http://dx.doi.org/10.1083/jcb.201710087.

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Fluorescence microscopy is a powerful approach for studying subcellular dynamics at high spatiotemporal resolution; however, conventional fluorescence microscopy techniques are light-intensive and introduce unnecessary photodamage. Light-sheet fluorescence microscopy (LSFM) mitigates these problems by selectively illuminating the focal plane of the detection objective by using orthogonal excitation. Orthogonal excitation requires geometries that physically limit the detection objective numerical aperture (NA), thereby limiting both light-gathering efficiency (brightness) and native spatial resolution. We present a novel live-cell LSFM method, lateral interference tilted excitation (LITE), in which a tilted light sheet illuminates the detection objective focal plane without a sterically limiting illumination scheme. LITE is thus compatible with any detection objective, including oil immersion, without an upper NA limit. LITE combines the low photodamage of LSFM with high resolution, high brightness, and coverslip-based objectives. We demonstrate the utility of LITE for imaging animal, fungal, and plant model organisms over many hours at high spatiotemporal resolution.

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Dang, Zhiya, and Duc Anh Dinh. "Interaction of light with lead halide perovskites: A review." Characterization and Application of Nanomaterials 2, no. 2 (November 19, 2019): 67. http://dx.doi.org/10.24294/can.v2i2.813.

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Lead halide perovskites are the new rising generation of semiconductor materials due to their unique optical and electrical properties. The investigation of the interaction of halide perovskites and light is a key issue not only for understanding their photophysics but also for practical applications. Hence, tremendous efforts have been devoted to this topic and brunch into two: (i) decomposition of the halide perovskites thin films under light illumination; and (ii) influence of light soaking on their photoluminescence (PL) properties. In this review, we for the first time thoroughly compare the illumination conditions and the sample environment to correlate the PL changes and decomposition of perovskite under light illumination. In the case of vacuum and dry nitrogen, PL of the halide perovskite (MAPbI3–xClx, MAPbBr3–xClx, MAPbI3) thin films decreases due to the defects induced by light illumination, and under high excitations, the thin film even decomposes. In the presence of oxygen or moisture, light induces the PL enhancement of halide perovskite (MAPbI3) thin films at low light illumination, while increasing the excitation, which causes the PL to quench and perovskite thin film to decompose. In the case of mixed halide perovskite ((MA)Pb(BrxI1-x)3) light induces reversible segregation of Br domains and I domains.

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Grunwald, Ruediger, Mathias Jurke, Martin Bock, Max Liebmann, Binal Poyyathuruthy Bruno, Hitesh Gowda, and Ulrike Wallrabe. "High-Flexibility Control of Structured Light with Combined Adaptive Optical Systems." Photonics 9, no. 1 (January 13, 2022): 42. http://dx.doi.org/10.3390/photonics9010042.

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Combining the specific advantages of high-resolution liquid-crystal-on-silicon spatial light modulators (LCoS-SLMs) and reflective or refractive micro-electro-mechanical systems (MEMS) presents new prospects for the generation of structured light fields. In particular, adaptive self-apodization schemes can significantly reduce diffraction by low-loss spatial filtering. The concept enables one to realize low-dispersion shaping of nondiffracting femtosecond wavepackets and to temporally switch, modulate or deflect spatially structured beams. Adaptive diffraction management by structured illumination is demonstrated for piezo-based and thermally actuated axicons, spiral phase plates (SPPs) and Fresnel bi-mirrors. Improved non-collinear autocorrelation with angular-tunable Fresnel-bi-mirrors via self-apodized illumination and phase contrast of an SLM is proposed. An extension of the recently introduced nondiffractive Talbot effect to a tunable configuration by combining an SLM and a fluid lens is reported. Experimental results for hexagonal as well as orthogonal array beams are presented.

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YU, GENYUAN, LISHA FENG, LU MENG, ZHIZHEN YE, and JIANGUO LU. "BEHAVIORS OF PHOTOCONDUCTIVE DETECTORS BASED ON MAPbI3 PEROVSKITE FILMS." Surface Review and Letters 25, no. 02 (February 2018): 1850057. http://dx.doi.org/10.1142/s0218625x18500579.

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The CH3NH3PbI3 films were synthesized by a facile low-cost solution process and were used to fabricate photoconductive detectors. The perovskite photodetector is very sensitive to light, with a high responsivity of 5.51[Formula: see text]mA/W and a sensitivity of 50 at 5[Formula: see text]V under 350[Formula: see text]nm light illumination. The device exhibits the fast rise and decay processes with similar appearance, and the relaxation time constants are 270 and 300[Formula: see text]ms, respectively. The photo-current shows an evident saturation, without further increase for prolonging the illumination period. The perovskite photodetectors display high responsive performances to short-wavelength lights. This study is expected to provide a fundamental knowledge of perovskite photodetectors with high speed and repeatability for practical applications.

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Guo, Jie, Zijing Zong, Yadong Song, Xihao Fu, Chengzhi Tao, Yanwen Guo, and Ling-Qi Yan. "Efficient Light Probes for Real-Time Global Illumination." ACM Transactions on Graphics 41, no. 6 (November 30, 2022): 1–14. http://dx.doi.org/10.1145/3550454.3555452.

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Reproducing physically-based global illumination (GI) effects has been a long-standing demand for many real-time graphical applications. In pursuit of this goal, many recent engines resort to some form of light probes baked in a precomputation stage. Unfortunately, the GI effects stemming from the precomputed probes are rather limited due to the constraints in the probe storage, representation or query. In this paper, we propose a new method for probe-based GI rendering which can generate a wide range of GI effects, including glossy reflection with multiple bounces, in complex scenes. The key contributions behind our work include a gradient-based search algorithm and a neural image reconstruction method. The search algorithm is designed to reproject the probes' contents to any query viewpoint, without introducing parallax errors, and converges fast to the optimal solution. The neural image reconstruction method, based on a dedicated neural network and several G-buffers, tries to recover high-quality images from low-quality inputs due to limited resolution or (potential) low sampling rate of the probes. This neural method makes the generation of light probes efficient. Moreover, a temporal reprojection strategy and a temporal loss are employed to improve temporal stability for animation sequences. The whole pipeline runs in realtime (>30 frames per second) even for high-resolution (1920×1080) outputs, thanks to the fast convergence rate of the gradient-based search algorithm and a light-weight design of the neural network. Extensive experiments on multiple complex scenes have been conducted to show the superiority of our method over the state-of-the-arts.

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Journal articles on the topic 'High light illumination'

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