2,952 results on '"fresnel lens"'
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2. Minimum solar tracking system for a Fresnel lens-based LCPV
- Author
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Orynbassar, Sayat, Almen, Dinara, Mekhilef, Saad, Kapparova, Ainur, Dosymbetova, Gulbakhar, Nurgaliyev, Madiyar, Saymbetov, Ahmet, Ibraimov, Margulan, Kuttybay, Nurzhigit, Yershov, Evan, Koshkarbay, Nursultan, Zholamanov, Batyrbek, and Bolatbek, Askhat
- Published
- 2024
- Full Text
- View/download PDF
3. Lenticular Thermal Solar Collector
- Author
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Rativa, Diego, de Araujo, Renato. E., Gómez-Malagón, Luis A., de Araújo, Rogerio Pontes, and Vital, Caio V.P.
- Published
- 2025
- Full Text
- View/download PDF
4. Design and analysis of thickened acoustic phase reversal Fresnel lens with high-focusing performance.
- Author
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Liu, Enxiao, Gu, Wenhao, Liu, Qingyun, Liu, Yongmeng, Deng, Shuchao, Wang, Xiurong, and Lin, Shuo
- Subjects
- *
FRESNEL lenses , *SOUND waves , *ULTRASONIC waves , *SOUND energy , *PIEZOELECTRIC transducers - Abstract
The accurate measurement of the contact stress of an aero-engine rotor mating surface is crucial for aviation safety. The focusing performance of ultrasonic lenses directly determines the accuracy of contact stress measurement. Phase reversal Fresnel zone plate (PR-FZP) is a new ultrasonic focusing lens suitable for contact stress measurement. A thickened phase reversal Fresnel zone lens (TPR-FZL) is proposed to improve the concentration ability. The lens replaces the path of sound waves travelling through the liquid with the Fresnel lens material, which reduces the energy loss of sound waves in the liquid and the interface of different materials, thus increasing the focus sound energy. The results showed that TPR-FZL, made of polymethyl pentene (PMP) and polyethene (PE), had relatively higher focal sound intensity. The larger the diameter of the piezoelectric plate, the stronger the focusing ability of TPR-FZL. When the material of TPR-FZL is PMP, the diameter of the piezoelectric plate of the transducer is 25 mm, TPR-FZL is the intermediate transmission type, and the thickness of the body is 35 mm, the focusing ability of TPR-FZL is the strongest. This study is of great significance for accurately measuring the contact stress on the mating surface of aero-engine rotors. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. New Design Scheme for and Application of Fresnel Lens for Broadband Photonics Terahertz Communication.
- Author
-
Tian, Peng, Han, Yang, Li, Weiping, Yang, Xiongwei, Wang, Mingxu, and Yu, Jianjun
- Abstract
In terahertz communication systems, lens antennas used in transceivers are basically plano-convex dielectric lenses. The size of a plano-convex lens increases as the aperture increases, and thinner lenses have longer focal lengths. Through theory and simulation, we designed a Fresnel lens suitable for the terahertz band to meet the requirements of large aperture and short focal length, and simulated the performance, advantages, and disadvantages of the terahertz Fresnel lens. A 300 GHz terahertz wireless communication system was built to verify the gain effect of the Fresnel lens antenna. The experimental results demonstrate that the Fresnel lens can be used for long-distance terahertz communication with larger aperture diameters, overcoming the limitations of traditional plano-convex lenses. The theoretical gain of a 30 cm Fresnel lens is 48.83 dB, while the actual measured gain is approximately 45 dB. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. Multirod Pumping Approach with Fresnel Lens and Ce:Nd:YAG Media for Enhancing the Solar Laser Efficiency.
- Author
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Almeida, Joana, Costa, Hugo, Vistas, Cláudia R., Tibúrcio, Bruno D., Matos, Ana, and Liang, Dawei
- Subjects
- *
CONTINUOUS wave lasers , *PARABOLIC reflectors , *HIGH power lasers , *FRESNEL lenses , *LASER pumping , *COMPOUND parabolic concentrators , *NEODYMIUM lasers , *LASERS - Abstract
A multirod Ce:Nd:YAG solar laser approach, using a Fresnel lens as a primary concentrator, is here proposed with the aim of considerably increasing the efficiency of solar-pumped lasers. Fresnel lenses are cost-effective, rendering solar lasers more economically competitive. In this work, solar-pumped radiation collected and concentrated using the Fresnel lens is received by a secondary three-dimensional compound parabolic concentrator which transmits and funnels the light toward the Ce:Nd:YAG laser rods within a water-cooled tertiary conical concentrator that enables efficient multipass pumping of the rods. To explore the full potential of the proposed approach, the performance of various multirod configurations is numerically evaluated. Through this study, configurations with three and seven Ce:Nd:YAG rods are identified as being the most efficient. A maximum continuous wave total laser power of 122.8 W is reached with the three-rod configuration, marking the highest value from a Ce:Nd:YAG solar laser, leading to solar-to-laser conversion and collection efficiencies of 7.31% and 69.50 W/m2, respectively. These results represent enhancements of 1.88 times and 1.79 times, respectively, over the previous experimental records from a Ce:Nd:YAG/YAG single-rod solar laser with a Fresnel lens. Furthermore, the above results are also 1.58 times and 1.68 times, respectively, greater than those associated with the most effective three-rod Ce:Nd:YAG solar laser utilizing a parabolic mirror as the main concentrator. The present study also shows the great usefulness of the simultaneous pumping of multiple laser rods in terms of reducing the thermal stress effects in active media, being the seven-rod configuration the one that offered the best compromise between maximum efficiency and thermal performance. This is crucial for the applicability of this sustainable technology, especially if we wish to scale our system to higher power laser levels. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. Electrically Controlled Liquid Crystal Twist-Planar Fresnel Lens.
- Author
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Mel'nikova, E. A., Panteleeva, E. P., Gorbach, D. V., Tolstik, A. L., Rushnova, I. I., and Kabanova, O. S.
- Subjects
- *
NEMATIC liquid crystals , *FRESNEL diffraction , *FRESNEL lenses , *LIQUID crystals , *LASER beams - Abstract
Based on the method of photo-orientation of the azo-dye AtA-2, an electrically controlled Fresnel lens has been developed which is a microstructured liquid crystal element made up of alternating rings with twist- and planar orientations of the liquid crystal director. It is shown that the use of a control voltage makes it possible to control the efficiency of the focusing of laser radiation, as well as to turn off the lens. An optimum control voltage (~3 V) is determined at which a maximum focal efficiency and satisfactory quality of image construction over a wide spectral range from 530 nm to 1.1 μm are attained. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. Modelling П-Shaped Concentrating Optics for Lcpv Solar Cells Using Fresnel Lens.
- Author
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Kapparova, A., Orynbassar, S., Dosymbetova, G., Almen, D., Yershov, E., Saymbetov, A., Nurgaliyev, M., Algazin, N., Sharipbay, A., and Zhastalapova, D.
- Subjects
- *
FRESNEL lenses , *SOLAR cells , *ENERGY consumption , *SOLAR system , *ENERGY industries - Abstract
Most concentrating optics do not show good performance at higher incidence angles and have low acceptance angles and, therefore, they require a high-accuracy solar tracking system, which is costly. In this study, by detailed investigation of optics of the proposed П-shaped concentrating optics, it was found that system remained high in terms of optical efficiency and its concentration ratio at certain higher incidence angles. During the work, ray path through the concentrating optics, width of the light spot at different incidence angles were calculated. Optical efficiency, geometrical concentration ratio, concentration ratio at different incidence angles were found by the results of COMSOL Multiphysics calculations. It was found that the system had a high optical efficiency of approximately 95% and its concentration ratio of 3x-5x was at the range of ±0-20 degrees of incidence angle, and it could reduce the work of a solar tracking system. As well, an increase in the optical efficiency could be seen from 0 to 5 degrees of the incidence angle and an increase in the concentration ratio could be seen from 0 to 12 degrees of the incidence angle in terms of the reflective mirrors which helped redirect the rays to the solar cells. Optical systems with such a high incidence angle could reduce the performance of the solar tracker system, and it reduced the overall cost and energy consumption of the LCPV. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Concentration performance evaluation of sunlight concentrators: Fresnel lens, plano-convex lens, and parabolic mirrors for daylighting application.
- Author
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Song, Jifeng and Dessie, Bizuayehu Bogale
- Subjects
PARABOLIC reflectors ,FRESNEL lenses ,DAYLIGHT ,ENERGY consumption ,CLEAN energy ,SOLAR energy - Abstract
This study investigates the concentration performance of three concentrator types – Fresnel lens, plano-convex lens, and parabolic mirrors in focusing sunlight onto a 1.5 mm diameter plastic optical fiber. The evaluation uses TracePro ray tracing software for simulation and analysis, considering visible light and infrared bands. Results show that parabolic mirrors achieved the highest concentration ratio at 7720 suns, followed by the Fresnel lens at 6400 suns, and the plano-convex lens at 2750 suns for a wavelength of 535 nm, surpassing geometric concentration values of 1202 suns. Efficiency measurements revealed that the Fresnel lens achieved 86% efficiency, the parabolic mirrors reached 97% efficiency, and the plano-convex lens achieved 93% efficiency. Additionally, the parabolic mirror demonstrated potential for creating the smallest concentration spot size due to its ability to focus light on a single point. This study highlights potential applications of sunlight concentrators in enhancing natural lighting in buildings and promoting energy efficiency. The comparative analysis of these concentrators offers insights into their performance characteristics, aiding in the selection and optimization of concentrators for daylighting applications. Moreover, this research supports the concept of green and sustainable energy by demonstrating the potential of solar energy to meet building energy demand and promote daylighting as a means to reduce reliance on conventional energy sources. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. Multi-Fresnel-Lens Pumping Approach for Simultaneous Emission of Seven TEM 00 -Mode Beams with 3.73% Conversion Efficiency.
- Author
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Costa, Hugo, Liang, Dawei, Matos, Ana, and Almeida, Joana
- Subjects
FRESNEL lenses ,FUSED silica ,QUALITY factor ,LASER beams ,TORUS - Abstract
TEM
00 -mode operation is a requirement in many laser-based applications due to the small divergence and high-power density of the emitted laser beam. A solar laser scheme was designed and numerically studied with the goal of increasing the solar-to-laser power conversion efficiency in the TEM00 -mode operation. The collection and primary concentration of sunlight was performed via twelve sets of folding mirrors and Fresnel lenses, toward a laser head composed of a fused silica torus volume and seven Ce:Nd:YAG rods, in a side-pump configuration. With this scheme, TEM00 -mode laser power totaling 212.39 W could potentially be produced from seven beams, with six of them being 32.60 W each and with M x 2 = 1.00, M y 2 = 1.01 quality factors. Notably, 35.40 W/m2 collection efficiency and, most importantly, 3.73% solar-to-laser power conversion efficiency were numerically achieved. The latter efficiency value represents a 1.81-time improvement over the experimental record, established with a prototype that had a single Ce:Nd:YAG rod in an end-side pump configuration. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
11. Research on the characteristics of hydrogen production by methanol steam reforming in a Fresnel lens concentrated tubular reactor.
- Author
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Xiuqin, Zhang, Feng, Wang, Guoqiang, Wang, Zhaolei, Zheng, and Jun, Liu
- Subjects
- *
STEAM reforming , *HYDROGEN production , *FRESNEL lenses , *TUBULAR reactors , *METHANOL production , *METHANOL as fuel - Abstract
The methanol steam reforming process involves variable heat absorption along the flow direction, resulting in a non-uniform temperature within the reactor. To improve the hydrogen production performance, this paper introduces an innovative solar-driven reactor, the Fresnel Lens Concentrated Collector Tubular Reactor (FLCCTR), which matches solar energy collection with the endothermic reforming process through optimized design. The heat flux density on the reactor's inner wall was determined using the Monte Carlo method. Subsequently, a 3D model was developed that integrates flow, heat and mass transfer, along with reforming kinetics. This model assessed the effects of inlet flow rate, temperature, steam-to-methanol ratio, and heat flux density type on hydrogen production performance. Results indicate that the inlet flow rate significantly affects performance, with the reactor maintaining a minimal radial temperature difference of 3.554K. It also indicated that non-uniform heat flux reduces the temperature increase and CO output by 36.84% at the outlet. • A novel reactor propelled by a Fresnel lens-based cavity solar collector is proposed. • Comparison of hydrogen production performance at two heat flux densities. • Lower CO production at non-uniform heat flux density. • The proposed new reactor has a small radial temperature difference. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. Electrically Controlled Liquid Crystal Twist-Planar Fresnel Lens
- Author
-
Mel’nikova, E. A., Panteleeva, E. P., Gorbach, D. V., Tolstik, A. L., Rushnova, I. I., and Kabanova, O. S.
- Published
- 2024
- Full Text
- View/download PDF
13. Optimization of Grayscale Lithography for the Fabrication of Flat Diffractive Infrared Lenses on Silicon Wafers.
- Author
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Bouchouri, Angelos, Akram, Muhammad Nadeem, Øhlckers, Per Alfred, and Chen, Xuyuan
- Subjects
FRESNEL lenses ,GRAYSCALE model ,SILICON wafers ,SURFACE topography ,PHOTORESISTS - Abstract
Grayscale lithography (GSL) is an alternative approach to the standard binary lithography in MEMS fabrication, enabling the fabrication of complicated, arbitrary 3D structures on a wafer without the need for multiple masks and exposure steps. Despite its advantages, GSL's effectiveness is highly dependent on controlled lab conditions, equipment consistency, and finely tuned photoresist (PR) exposure and etching processes. This works presents a thorough investigation of the challenges of GSL for silicon (Si) wafers and presents a detailed approach on how to minimize fabrication inaccuracies, aiming to replicate the intended design as closely as possible. Utilizing a maskless laser writer, all aspects of the GSL are analyzed, from photoresist exposure parameters to Si etching conditions. A practical application of GSL is demonstrated in the fabrication of 4-μm-deep f #/1 Si Fresnel lenses for long-wave infrared (LWIR) imaging (8–12 μm). The surface topography of a Fresnel lens is a good case to apply GSL, as it has varying shapes and size features that need to be preserved. The final fabricated lens profiles show a good match with the initial design, and demonstrate successful etching of coarse and fine features, and demonstrative images taken with an LWIR camera. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. 70‐2: Viewing Zone Enhancement of Coarse Integral Imaging Using Eye Tracking.
- Author
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Omori, Hiroto and Kakeya, Hideki
- Subjects
FRESNEL lenses ,PARALLAX ,INTEGRALS - Abstract
This paper proposes a method to expand the viewing zone in coarse integral imaging with small interleaved elemental lenses by utilizing eye‐tracking technology. The method involves generating elemental images based on the observer's viewing position, where the elemental images are shifted to follow the motion of the viewer. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. Harnessing Solar Energy for Pyrolysis of Empty Fruit Bunch: A Fresnel Lens Approach in Malaysia
- Author
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Hamed, Alia Syafiqah Abdul, Yusof, Nurul Iffah Farhah Mohd, Yahya, Muhammad Syarifuddin, Latiff, Nurul Adilah Abdul, Munajat, Nur Farizan, Ong, Hui Lin, editor, Yusof, Siti Jamilah Hanim Mohd, editor, Kasim, Khairul Farihan, editor, Gunny, Ahmad Anas Nagoor, editor, and Othman, Rahimah, editor
- Published
- 2024
- Full Text
- View/download PDF
16. Vat photopolymerization of multifunctional fresnel lenses for ocular management
- Author
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Murad Ali, Muhammed Hisham, Rashid K. Abu Al-Rub, and Haider Butt
- Subjects
fresnel lens ,3D printing ,vat photopolymerization ,color vision deficiency ,myopia ,conventional lenses ,Biotechnology ,TP248.13-248.65 - Abstract
In this study, multifunctional Fresnel lenses were explored as a potential solution for correcting vision in patients with color vision deficiency (CVD) and high myopia. Current studies have primarily focused on color vision correction through the 3D printing of glasses and contact lenses. However, the potential of 3D-printed multifunctional devices, such as Fresnel lenses, goes beyond addressing a single vision correction issue. For this study, computer-aided design (CAD) model of Fresnel lens with high diopter based on constant height configuration was developed. The CAD model was successfully fabricated using vat photopolymerization 3D printer, employing laboratory-prepared transparent HEMA resin. The resin was modified with two Atto dyes (565 nm and 488 nm), known for their ability to filter out problematic wavelengths (400–500 nm and 540–580 nm) to address color vision deficiency. The printed lenses were characterized by their chemical, physical, and optical properties using various characterization techniques. The focusing performance was evaluated using focal length measurements, and the results obtained were less than 2 mm deviation from the design value, having the potential to assist in higher myopic vision correction. The resulting optical spectra were compared with commercial glasses, revealing close agreement for CVD correction. These results expand the potential applications of multifunctional Fresnel lenses in ophthalmology, demonstrating their effectiveness as vision-correcting lenses and imaging systems.
- Published
- 2024
- Full Text
- View/download PDF
17. New Design Scheme for and Application of Fresnel Lens for Broadband Photonics Terahertz Communication
- Author
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Peng Tian, Yang Han, Weiping Li, Xiongwei Yang, Mingxu Wang, and Jianjun Yu
- Subjects
terahertz wireless transmission ,plano-convex lens ,Fresnel lens ,PTFE ,Chemical technology ,TP1-1185 - Abstract
In terahertz communication systems, lens antennas used in transceivers are basically plano-convex dielectric lenses. The size of a plano-convex lens increases as the aperture increases, and thinner lenses have longer focal lengths. Through theory and simulation, we designed a Fresnel lens suitable for the terahertz band to meet the requirements of large aperture and short focal length, and simulated the performance, advantages, and disadvantages of the terahertz Fresnel lens. A 300 GHz terahertz wireless communication system was built to verify the gain effect of the Fresnel lens antenna. The experimental results demonstrate that the Fresnel lens can be used for long-distance terahertz communication with larger aperture diameters, overcoming the limitations of traditional plano-convex lenses. The theoretical gain of a 30 cm Fresnel lens is 48.83 dB, while the actual measured gain is approximately 45 dB.
- Published
- 2024
- Full Text
- View/download PDF
18. Multirod Pumping Approach with Fresnel Lens and Ce:Nd:YAG Media for Enhancing the Solar Laser Efficiency
- Author
-
Joana Almeida, Hugo Costa, Cláudia R. Vistas, Bruno D. Tibúrcio, Ana Matos, and Dawei Liang
- Subjects
multirod ,Ce:Nd:YAG ,Fresnel lens ,solar laser ,solar pumping ,Technology - Abstract
A multirod Ce:Nd:YAG solar laser approach, using a Fresnel lens as a primary concentrator, is here proposed with the aim of considerably increasing the efficiency of solar-pumped lasers. Fresnel lenses are cost-effective, rendering solar lasers more economically competitive. In this work, solar-pumped radiation collected and concentrated using the Fresnel lens is received by a secondary three-dimensional compound parabolic concentrator which transmits and funnels the light toward the Ce:Nd:YAG laser rods within a water-cooled tertiary conical concentrator that enables efficient multipass pumping of the rods. To explore the full potential of the proposed approach, the performance of various multirod configurations is numerically evaluated. Through this study, configurations with three and seven Ce:Nd:YAG rods are identified as being the most efficient. A maximum continuous wave total laser power of 122.8 W is reached with the three-rod configuration, marking the highest value from a Ce:Nd:YAG solar laser, leading to solar-to-laser conversion and collection efficiencies of 7.31% and 69.50 W/m2, respectively. These results represent enhancements of 1.88 times and 1.79 times, respectively, over the previous experimental records from a Ce:Nd:YAG/YAG single-rod solar laser with a Fresnel lens. Furthermore, the above results are also 1.58 times and 1.68 times, respectively, greater than those associated with the most effective three-rod Ce:Nd:YAG solar laser utilizing a parabolic mirror as the main concentrator. The present study also shows the great usefulness of the simultaneous pumping of multiple laser rods in terms of reducing the thermal stress effects in active media, being the seven-rod configuration the one that offered the best compromise between maximum efficiency and thermal performance. This is crucial for the applicability of this sustainable technology, especially if we wish to scale our system to higher power laser levels.
- Published
- 2024
- Full Text
- View/download PDF
19. Mathematical Model of Parabolic Trough Collector with Fresnel Lens as Second Collector.
- Author
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Aljarwi, Abdullah, Al-Salihi, Adnan K., and Yehay, F.
- Subjects
- *
PARABOLIC troughs , *FRESNEL lenses , *HEAT transfer fluids , *MATHEMATICAL models , *SOLAR energy - Abstract
Parabolic trough collectors (PTCs) have came out as a promising technology for harnessing solar energy for various applications including electricity generation and thermal heating. However, improving their thermal performance remains a critical challenge to maximize energy conversion efficiency. This paper presents a mathematical model for enhancing the thermal performance of PTCs by using a curved Fresnel lens as a second collector over the top side of the receiver. This enhancing has taken advantage of the space above the top side of receiver and increased the thermal efficiency of PTCs. The unsteady heat transfer equations with one dimension are used to simulate the effect of Fresnel lens on the receiver components beside the heat transfer fluid and compared with that without Fresnel lens. The results of this model are based on parameters of LS-2 model and environment of installation place whereas the water was chosen as heat transfer fluid with physical properties depending on Temperature. Albaydha city in Yemen is chosen as an installation place taking in consideration the variation of environment temperature in each month of the year and the inlet temperature of water and receiver's components are taken as the minimum temperature of the air. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. The Potential of Steam Generating by The PMMA Fresnel Lens Concentrator for Indoor Solar Cooker Application.
- Author
-
Asrori, Asrori, Udianto, Pondi, Faizal, Elka, Rizza, Muhammad Akhlis, Witono, Kris, and Perdana, Dony
- Subjects
- *
RENEWABLE energy sources , *CLEAN energy , *FRESNEL lenses , *SOLAR technology , *POWER resources , *SOLAR concentrators - Abstract
Solar power is an alternative energy source that can be used for cooking. It is a simple, secure, and useful way to cook food without using conventional fuels that pollute the air. Solar cookers offer various benefits to the user's health, productivity, and income as well as to the environment. Solar energy is abundant in a tropical country like Indonesia, making it a dependable and sustainable of energy resource. The study's goal is to analyze the potency of steam produced by a solar cooker that uses a Fresnel lens concentrator. The thermal performance of the Fresnel lens concentrator with a conical receiver on the solar cooker prototype is discussed in this research. In the construction of solar cookers, PMMA (Polymethyl-Methacrylate) Fresnel lenses, manual trackers, and conical receiver types are used. The research conducts an experimental analysis of the thermal performance of the prototype solar cooker using a Fresnel lens concentrator with a conical receiver. This empirical approach provides valuable data on the efficiency and effectiveness of the solar cooker design. The experiment result shows the cumulative average solar irradiation, the average collection of solar energy per time of Fresnel lens concentrator, and the heat utilized of steam from conical receiver are 709.09 W/m², 456.14 Watt, and 383.88 Watt, respectively. The results of this study suggest that Fresnel lens concentrators are a promising development for indoor solar cookers and therefore provide a pathway for increased utilization of solar cooking technology. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. АНАЛІЗ ЗМІНИ ВІДСТАНІ ЛІНЗИ ФРЕНЕЛЯ ДО КОНЦЕНТРАЦІЙНОЇ ПОВЕРХНІ ДЛЯ ЗАБЕЗПЕЧЕННЯ ФУНКЦІОНУВАННЯ ДВИГУНА СТІРЛІНГА
- Author
-
В. М., Головко and М. М., Бережнюк
- Abstract
Renewable energy sources account for a significant part of the energy sector, but electricity generation from renewable energy plants is not stable and predictable over time, depending on various factors, such as wind speed or insolation. One method of ensuring stable electricity generation from such plants is to use an additional energy source. In a thermodynamic plant based on the Stirling engine, when the heat from the concentration of solar radiation is not enough, additional heat can be obtained by burning fuel. This paper investigates the temperature control of the Stirling engine boiler by changing the distance to the Fresnel lens, which will allow further calculation of the required power of the additional heat source. The dependence of the temperature of the concentration spot on its area and the distance between the lens and the heating part of the engine at different intensities of solar radiation was determined. The depth of focus of the lens is analysed as the main characteristic for the selection of systems that regulate the distance between the lens and the surface of the Stirling engine boiler. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. Effects of climate variables and nanofluid-based cooling on the efficiency of a liquid spectrum filter-based concentrated photovoltaic thermal system.
- Author
-
Kumar, Sushil, Kumar, Raj, Thakur, Robin, and Lee, Daeho
- Subjects
- *
PHOTOVOLTAIC power systems , *SOLAR panels , *SOLAR energy , *FRESNEL lenses , *THERMAL efficiency - Abstract
The primary aim of the research is to improve photovoltaic thermal systems, with a particular focus on enhancing their efficiency and overall effectiveness by utilizing the Fresnel lens and nanofluid-based liquid spectrum filter with a dual-axis solar tracker. The study explores innovative techniques, including the application of nanofluid to cool the solar panel. This cooling not only increases the electrical efficiency of the solar panels but also extends their life span by effectively preventing overheating. Moreover, the research investigates the utilization of solar trackers, which optimize the collection of solar energy by continuously aligning the panels with the sun's position. The consideration of the parameters—flow rate, ambient air temperature, wind speed, and solar intensity—led to a significant improvement in the thermal and electrical efficiencies. The electrical efficiency increases from 15.5 to 19.6%, while the thermal efficiency increases from 52.6 to 58.7% by optimizing the considered parameters. This is a companion study of the photovoltaic thermal system that reveals the influence of new parameters. By implementing these advancements, the research significantly contributes to the development of sustainable and high-performance solar energy solutions suitable for diverse applications, spanning both residential and industrial sectors. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Advancements in Fresnel Lens Technology across Diverse Solar Energy Applications: A Comprehensive Review.
- Author
-
Rashid, Farhan Lafta, Al-Obaidi, Mudhar A., Mahdi, Ali Jafer, and Ameen, Arman
- Subjects
- *
FRESNEL lenses , *FOCAL length , *PHOTOVOLTAIC cells , *IMAGING systems , *SOLAR energy , *SOLAR system - Abstract
Concentration of solar energy may be obtained by reflection, refraction, or a combination of the two. The collectors of a reflection system are designed to concentrate the sun's rays onto a photovoltaic cell or steam tube. Refractive lenses concentrate light by having it travel through the lens. The sun's rays are partially reflected and then refracted via a hybrid technique. Hybrid focus techniques have the potential to maximize power output. Fresnel lenses are an efficient tool for concentrating solar energy, which may then be used in a variety of applications. Development of both imaging and non-imaging devices is occurring at this time. Larger acceptance angles, better concentration ratios with less volume and shorter focal length, greater optical efficiency, etc., are only some of the advantages of non-imaging systems over imaging ones. This study encompasses numerical, experimental, and numerical and experimental studies on the use of Fresnel lenses in various solar energy systems to present a comprehensive picture of current scientific achievements in this field. The framework, design criteria, progress, and difficulties are all dissected in detail. Accordingly, some recommendations for further studies are suggested. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Active and Passive Lenses From Coupled Square Ring Slots
- Author
-
Christoph Kohlberger, Saeid Karamzadeh, and Andreas Stelzer
- Subjects
Active metamaterial ,equivalent circuit ,frequency selective surface ,Fresnel lens ,lens antenna ,reflect array ,Telecommunication ,TK5101-6720 ,Electric apparatus and materials. Electric circuits. Electric networks ,TK452-454.4 - Abstract
This work presents the utilization of square ring slots as resonators on active and passive metasurfaces operating within the K$_\text{a}$-band. Thereby, fully functional prototypes of reflectors and lenses based on a two-layer printed circuit board were fabricated and verified. The analytical model of the square ring slot structure is depicted extensively, which allows finding simulation optimized designs that can be applied to the passive prototypes. Additionally, the gained information on self-resonances is used for combinations with layers, activated through lumped varactor diodes. In the end, the reflection and transmission parameters of single active and passive designs as well as beam patterns of the lenses are measured and interpreted, resulting in a switching dynamic range of 15 dB at a bandwidth of 1 GHz for active reflectors and a maximum gain of 22 dBi at 26 GHz for the passive lens. While the active lens operates best approximately 1 GHz around the design frequency at 26 GHz, the passive one maintains a maximum gain higher than 20.8 dBi between 23 and 27 GHz.
- Published
- 2024
- Full Text
- View/download PDF
25. Milk Heating Using a Solar Cooker Coupled with Point-Focus Fresnel Lens
- Author
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Ahmad Banakar, Erfan Ghasemi, and Farzaneh Arabpour
- Subjects
solar concentrator ,energy storage ,fresnel lens ,thermal efficiency ,Agriculture - Abstract
Today, concerns regarding global warming resulting from fossil fuel usage and the depletion of these resources have led individuals to consider alternative, clean energy sources. Renewable energies such as solar energy are non-polluting, inexhaustible resources, serving as an excellent alternative to fossil fuels. Solar concentrate sunlight, directing it towards the solar oven. Utilizing renewable energy for cooking not only saves time and money but also ensures safety and security. The aim of this research is to construct and assess a solar oven equipped with a point Fresnel lens. The evaluations were conducted over a three-day period in March 2023. The maximum total thermal efficiency obtained for heating the milk for three days with different radiation intensity, wind speed and ambient temperature tested was 45%, 72.7% and 90%, respectively. The findings indicated that the solar oven could raise the milk temperature to 80℃ within one hour. The maximum attainable performance of this system was 90%.
- Published
- 2023
- Full Text
- View/download PDF
26. Development and demonstration of ultra high concentrator photovoltaic system beyond 3000×
- Author
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Alzahrani, M., Mallick, Tapas, and Asif, Tahir
- Subjects
Solar Energy ,Concentrated Photovoltaic ,Ultra High Concertation ,Fresnel Lens - Abstract
Concentrating photovoltaic technology harnesses solar energy by increasing the solar density upon solar cells using optical concentrators. Ongoing research on concentrating photovoltaic systems aim to improve the achievable energy harnessing and utilisation potential. Increasing the concentration ratio for high energy generation raises many advances and limitations in the concentrating photovoltaic design. However, the field of concentrating photovoltaic research is still in progress where new configurations, methods and materials are fabricated to reach a competitive cost by enhancing the efficiencies of the system to standard silicon photovoltaic systems. The work presented in this thesis focuses on developing and demonstrating an ultrahigh concentrated photovoltaic system beyond 3000×. This system is based on a Silicon-on-Glass Fresnel lens resulting in a geometrical design of 5831×. The Fresnel lens as a primary optical interface was investigated theoretically, numerically, and experimentally to understand the operating limits in terms of power output, optical performance (optical efficiency and concentration ratio), and working temperature. The discrepancy between a Fresnel lens's theoretical and experimental optical characterisation results was studied. All the equations were elaborated for single- and multi-junction solar cells, emphasising the performance when the focal spot area is larger or lesser than the solar cell area. The prediction approach of optical characterisation has shown a strong agreement between the theoretical and experimental results of the multi-junction solar cells with a discrepancy of 2% at 7.7 W (77 suns) and 6% on the average cross a solar irradiance on the cell from 3.1 W - 7.7 W corresponding to 31 suns - 77 suns in concentration ratio. The numerical model using COMSOL Multiphysics software was established to study the Fresnel lens optically and thermally. The developed optical model was validated theoretically and experimentally to show a firm agreement with a discrepancy of ≤1%. Also, the developed thermal model was validated experimentally to show a difference of only 2.18%. Further, optical and electrical characterisations of the flawed glass have been conducted. The optical characterisation has shown a drop of 3.2% in optical efficiency. I-V and power curves of cracked and non-cracked Fresnel lenses were also compared to show a drop of 3.2% in short circuit current and power. A theoretical analysis of the optical performance for a ¼ of the ultrahigh concentrated photovoltaic system design grouping three optical interfaces is performed to estimate the optical loss and its influence on the optical efficiency and concentration ratio. Also, a numerical model was established using COMSOL Multiphysics software to simultaneously evaluate the thermal and optical performance of a ¼ of the ultrahigh concentrated photovoltaic system. The system was analysed under direct normal irradiance ranging from 400 W/m^2 to 1000 W/m^2 in an interval of 100 W/m^2 , showing a simulative optical efficiency of ~93% and a simulative concentration ratio of 1361 suns at 1000 W/m^2 . The thermal model was interlinked with the optical model to generate the results accordingly. The final stage receiver shows a maximum temperature ranging between 157.4 ℃ and 78.5 ℃. Moving toward a ultrahigh concentrated photovoltaic design raises the importance of a cooling management system due to thermal excitation. Although the thermal performance and thermal management for the ultrahigh concentrated photovoltaic system are beyond this thesis's scope, the cooling mechanism arrangement based on either pre- or post-illumination techniques was explored. The post-cooling mechanism study was established using COMSOL Multiphysics software for numerical analysis. A flat-plate and micro fin heatsink studied the effect of concentration ratio up to 2000 suns to determine their limits as a passive cooling system and establish when an active cooling system is needed based on the recommended operating temperature of the solar cell of 80 °C. On the other hand, Graphene was experimentally exploited as a pre-illumination cooling technique for a solar cell with different graphene coating thicknesses. The concept of utilising graphene as a neutral density filter for focal spot concentrating photovoltaic (Fresnel lens primary optic) reduces the solar cell temperature significantly and maintains the cell temperature for a more extended period. The graphene coating orientation further influenced the temperature gradient behaviour of the focal spot and incident temperature. The Fresnel lens working parameters (focal length and the focal spot) were defined to establish the mechanical structural design accordingly. The system was mechanically designed based on three optical interfaces, built in-house, and incorporated with a sun tracker. Different aspects were examined initially before the outdoor testing, the sun tracker alignment accuracy and payload capacity, windage load, and counterbalance weight and moments effects using SOLIDWORKS software. The ultrahigh concentrated photovoltaic system was tested outdoor with three types of secondary mirrors, resulting in an effective concentration ratio of 984 suns, 1220 suns, and 1291 suns and an average optical efficiency of 18.5%, 20.25%, and 22% for Aluminium reflective film, Pilkington Optimirror, and ReflecTech® Polymer secondary optic types, respectively. The fabricated ultrahigh concentrated photovoltaic system and tested experimentally outdoor is the highest in both geometrical and effective concentration ratios so far. It would not be possible to design and perform the ultrahigh concentrated photovoltaic system without fully characterising its primary optic, which helps set the performance basis and associated losses. Although the experimented system showed the highest value in terms of both geometrical and effective concentration ratios, the subsequent optics to the Fresnel lens were standard optics. The attained outcomes are practical in progressing concentrating photovoltaic technologies to a higher concentration ratio.
- Published
- 2022
27. Multi-Fresnel-Lens Pumping Approach for Simultaneous Emission of Seven TEM00-Mode Beams with 3.73% Conversion Efficiency
- Author
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Hugo Costa, Dawei Liang, Ana Matos, and Joana Almeida
- Subjects
Ce:Nd:YAG ,Fresnel lens ,solar laser ,TEM00 mode ,Applied optics. Photonics ,TA1501-1820 - Abstract
TEM00-mode operation is a requirement in many laser-based applications due to the small divergence and high-power density of the emitted laser beam. A solar laser scheme was designed and numerically studied with the goal of increasing the solar-to-laser power conversion efficiency in the TEM00-mode operation. The collection and primary concentration of sunlight was performed via twelve sets of folding mirrors and Fresnel lenses, toward a laser head composed of a fused silica torus volume and seven Ce:Nd:YAG rods, in a side-pump configuration. With this scheme, TEM00-mode laser power totaling 212.39 W could potentially be produced from seven beams, with six of them being 32.60 W each and with Mx2 = 1.00, My2 = 1.01 quality factors. Notably, 35.40 W/m2 collection efficiency and, most importantly, 3.73% solar-to-laser power conversion efficiency were numerically achieved. The latter efficiency value represents a 1.81-time improvement over the experimental record, established with a prototype that had a single Ce:Nd:YAG rod in an end-side pump configuration.
- Published
- 2024
- Full Text
- View/download PDF
28. The Use of Fresnel Lenses in LED Sources of Local Illumination to Оptimize the Distribution of Illumination of the Working Plane
- Author
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P. S. Bogdan, E. G. Zaytseva, I. A. Kovalenok, T. D. Tarasenko, and E. V. Duboysky
- Subjects
mathematical modeling ,led matrix ,fresnel lens ,rgb led ,illumination distribution ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
For widely used LED sources there is a sharp decrease in the illumination of the working plane from the center to the edge. The purpose of this study was to analyze the effectiveness of Fresnel lenses usage as a fairly simple and technological element to increase the uniformity of illumination created by LED lamps of local lighting.A method has been developed for calculating of the distribution of illumination created by the combination of “LED matrix – Fresnel lens” when the distance between the lens and the matrix is less than the focal length of the lens. Comparison of the calculation results and experiments for the case when the lens is located at a distance of 50 cm from the working plane indicates the correctness of the developed calculation method. This made it possible to use this technique to solve the problem of improved uniformity of illumination distribution in the working plane of local lighting LED sources.It was found that the change in the distance between the matrix and the lens in the range of 0.5–1.5 cm affects the maximum illumination and its uniformity to a lesser extent than the change in focal lengths in the range of 10–100 cm. Analytical dependences of the uniformity of the working surface illumination as a function of the Fresnel lens focal length and its distance to the LED matrix were obtained for three cases. In the first case one lens is used for the entire matrix while the axes of symmetry of the light intensity curves of LEDs are parallel to the axis of the lens. In the second case one lens is also used for the entire matrix, but the continuations of the axes of symmetry of the light intensity curves pass through the front focus of the lens. In the third one an individual Fresnel lens is used for each LED. It is established that for all three cases dependencies have almost the same character. Therefore, the choice of using one of these three options may be due to manufacturability, cost-effectiveness, thermal stability, and other considerations.Calculations using the above-mentioned analytical dependences made it possible to determine values of the parameters of the “LED matrix – Fresnel lens” system at which the indicators of illumination and uniformity meet the standards’ requirements.
- Published
- 2023
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29. Investigation of Concentrator Photovoltaic Modules with Reflective Secondary Optical Elements.
- Author
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Sadchikov, N. A., Potapovich, N. S., Malevsky, D. A., Davidyk, N. Yu., Andreeva, A. V., and Chekalin, A. V.
- Subjects
- *
OPTICAL elements , *FRESNEL lenses , *ALUMINUM forming , *OPTICAL goods stores - Abstract
The characteristics of concentrator photovoltaic modules based on a 120 × 120 mm Fresnel lens with secondary concentrators in the form of hollow aluminum focons with internal mirror walls are studied. The optimal sizes and configurations of secondary concentrators are determined to increase the efficiency of focusing systems of concentrator modules. The maximum value of the allowable misorientation angle was obtained, equal to ±0.75°, corresponding to a power drop to a level of 90% relative to the maximum power value of the concentrator photovoltaic module at normal beam incidence. For a module with the most efficient focon 40 mm high and side face slope angles of 17°, the maximum efficiency of the module under laboratory conditions was obtained, equal to 35.15%. Under natural conditions, the efficiency value reached 33.8%. The results obtained correspond to the level achieved for the best foreign analogues. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
30. Milk Heating Using a Solar Cooker Coupled with Point-Focus Fresnel Lens.
- Author
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Banakar, Ahmad, Ghasemi, Erfan, and Arabpour, Farzaneh
- Subjects
- *
FRESNEL lenses , *HEAT treatment of milk , *SOLAR heating , *RESOURCE exploitation , *CLEAN energy , *GOAT milk - Abstract
Today, concerns regarding global warming resulting from fossil fuel usage and the depletion of these resources have led individuals to consider alternative, clean energy sources. Renewable energies such as solar energy are non-polluting, inexhaustible resources, serving as an excellent alternative to fossil fuels. Solar concentrate sunlight, directing it towards the solar oven. Utilizing renewable energy for cooking not only saves time and money but also ensures safety and security. The aim of this research is to construct and assess a solar oven equipped with a point Fresnel lens. The evaluations were conducted over a three-day period in March 2023. The maximum total thermal efficiency obtained for heating the milk for three days with different radiation intensity, wind speed and ambient temperature tested was 45%, 72.7% and 90%, respectively. The findings indicated that the solar oven could raise the milk temperature to 80? within one hour. The maximum attainable performance of this system was 90%. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
31. Reducing thickness of long-distance aerial display system in AIRR using Fresnel lens.
- Author
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Sakane, Shinya, Suyama, Shiro, and Yamamoto, Hirotsugu
- Subjects
- *
FRESNEL lenses , *DISPLAY systems , *BEAM splitters , *LIGHT sources , *OPTICS - Abstract
Aerial displays for providing road information require long-distance image formation and a compact installation space. This paper proposes a compact optical system for forming long-distance floating images by introducing a Fresnel lens in an aerial imaging by retro-reflection (AIRR) optical system. In the conventional AIRR optics, since the aerial image position is the plane-symmetrical position of the light source with respect to the beam splitter, the installation space for forming a long-distance aerial image becomes huge. Our proposed method uses the virtual image formed by a Fresnel lens as the light source in an AIRR optical system. This leads to a much longer distance from the beam splitter to the aerial image than the distance from the beam splitter to the light source. We developed a prototype long-distance floating aerial display system using a large-scale Fresnel lens. As a result, the distance from the LED panel to the beam splitter was halved. Furthermore, we used two beam splitters to form two aerial images by using a single LED panel. Long-distance floating images could be formed 3.4 m and 4.6 m away from the beam splitters and could be seen with the naked eye. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
32. An Improved 3D OPC Method for the Fabrication of High-Fidelity Micro Fresnel Lenses.
- Author
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Peng, Fei, Sun, Chao, Wan, Hui, and Gui, Chengqun
- Subjects
FRESNEL lenses ,MICROLENSES ,SIGNAL-to-noise ratio ,IMAGING systems ,OPTICAL images - Abstract
Based on three-dimensional optical proximity correction (3D OPC), recent advancements in 3D lithography have enabled the high-fidelity customization of 3D micro-optical elements. However, the micron-to-millimeter-scale structures represented by the Fresnel lens design bring more stringent requirements for 3D OPC, which poses significant challenges to the accuracy of models and the efficiency of algorithms. Thus, a lithographic model based on optical imaging and photochemical reaction curves is developed in this paper, and a subdomain division method with a statistics principle is proposed to improve the efficiency and accuracy of 3D OPC. Both the simulation and the experimental results show the superiority of the proposed 3D OPC method in the fabrication of Fresnel lenses. The computation memory requirements of the 3D OPC are reduced to below 1%, and the profile error of the fabricated Fresnel lens is reduced 79.98%. Applying the Fresnel lenses to an imaging system, the average peak signal to noise ratio (PSNR) of the image is increased by 18.92%, and the average contrast of the image is enhanced by 36%. We believe that the proposed 3D OPC method can be extended to the fabrication of vision-correcting ophthalmological lenses. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
33. Hybrid Metalens for Miniaturised Ultraviolet Fluorescence Detection.
- Author
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Li, Kezheng, Martins, Augusto, Bohora, Sanket, Dhakal, Ashim, Martins, Emiliano R., and Krauss, Thomas F.
- Subjects
- *
FRESNEL lenses , *FLUORESCENCE , *NUMERICAL apertures , *FECAL contamination , *WATER pollution , *DRINKING water - Abstract
The advantages of metalenses to enable miniaturized systems have been well established, especially in the visible and infrared wavelength regimes. The ultraviolet (UV) presents a final frontier because feature size scales as the wavelength, so realizing a large size metalens with a high numerical aperture (NA) in the UV is a major challenge. Here, a single‐layer, thin‐film (450 nm) hybrid metalens with an NA of 0.9 and a diameter of 6.2 mm is presented. By combining a Fresnel lens and optimised binary gratings, the well‐known shadowing effect of Fresnel lenses at high NA is avoided while being able to realize a large area lens. It is demonstrated that the combination of high NA and large area affords efficient detection of tryptophan‐like fluorescence, which is a well‐studied proxy for water contamination with faecal coliforms. The detection of tryptophan at levels better than 1 ppb, which corresponds to the low‐risk category for drinking water according to the World Health Organization (WHO), is shown. It is also confirmed that the hybrid metalens fluorescence collection efficiency is 3.5 times higher than a high NA plano‐convex lens used in state‐of‐the‐art fluorometers, which demonstrates that the versatile metalens approach opens up new opportunities in the UV. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
34. Development of high-precision Fresnel lenses for alcohol sensing using vat photopolymerization additive manufacturing
- Author
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Ali, Murad, Al-Rub, Rashid K. Abu, and Butt, Haider
- Published
- 2024
- Full Text
- View/download PDF
35. Optimization of Grayscale Lithography for the Fabrication of Flat Diffractive Infrared Lenses on Silicon Wafers
- Author
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Angelos Bouchouri, Muhammad Nadeem Akram, Per Alfred Øhlckers, and Xuyuan Chen
- Subjects
grayscale ,Fresnel lens ,MEMS ,infrared vision ,multilevel ,grayscale etching ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
Grayscale lithography (GSL) is an alternative approach to the standard binary lithography in MEMS fabrication, enabling the fabrication of complicated, arbitrary 3D structures on a wafer without the need for multiple masks and exposure steps. Despite its advantages, GSL’s effectiveness is highly dependent on controlled lab conditions, equipment consistency, and finely tuned photoresist (PR) exposure and etching processes. This works presents a thorough investigation of the challenges of GSL for silicon (Si) wafers and presents a detailed approach on how to minimize fabrication inaccuracies, aiming to replicate the intended design as closely as possible. Utilizing a maskless laser writer, all aspects of the GSL are analyzed, from photoresist exposure parameters to Si etching conditions. A practical application of GSL is demonstrated in the fabrication of 4-μm-deep f#/1 Si Fresnel lenses for long-wave infrared (LWIR) imaging (8–12 μm). The surface topography of a Fresnel lens is a good case to apply GSL, as it has varying shapes and size features that need to be preserved. The final fabricated lens profiles show a good match with the initial design, and demonstrate successful etching of coarse and fine features, and demonstrative images taken with an LWIR camera.
- Published
- 2024
- Full Text
- View/download PDF
36. Fresnel Lens Array-Based Phase Mask Location Method for Adjustable Multi-Pass Cavity.
- Author
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Wang, Ximing, Yu, Xichang, Yang, Tianyu, Ruan, Cheng, Gao, Shijie, and Ma, Lie
- Subjects
FRESNEL lenses ,SPATIAL light modulators ,MEDICAL masks - Abstract
The modulation accuracy of Multi-Plane Light Conversion (MPLC) mainly depends on the positioning accuracy of the phase mask on the Spatial Light Modulator (SLM). To improve positioning accuracy, the impact of phase mask shift on modulation accuracy is investigated, and a position method is proposed. In order to investigate the influence of phase mask offset on the input light conversion effect, a convolution transmission model for the adjustable multi-pass cavity is established. Then, the positioning process for the phase masks is analyzed and simulated, and a method of positioning the phase masks is presented. This method reduces the positioning time and increases the positioning accuracy to 8 μm. Finally, experiments are performed to verify the feasibility of the method. Experimental results show that the similarity of the adjustable multi-pass cavity positioned by this method can reach 93.44%. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
37. Application of the NSGA-II Algorithm and Kriging Model to Optimise the Process Parameters for the Improvement of the Quality of Fresnel Lenses.
- Author
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Chang, Hanjui, Sun, Yue, Wang, Rui, and Lu, Shuzhou
- Subjects
- *
FRESNEL lenses , *INJECTION molding , *KRIGING , *OPTICAL glass , *OPTICAL interference , *GRINDING & polishing , *MASS production - Abstract
The Fresnel lens is an optical system consisting of a series of concentric diamond grooves. One surface of the lens is smooth, while the other is engraved with concentric circles of increasing size. Optical interference, diffraction, and sensitivity to the angle of incidence are used to design the microstructure on the lens surface. The imaging of the optical surface depends on its curvature. By reducing the thickness of the lens, light can still be focused at the same focal point as with a thicker lens. Previously, lenses, including Fresnel lenses, were made of glass due to material limitations. However, the traditional grinding and polishing methods for making Fresnel lenses were not only time-consuming, but also labour-intensive. As a result, costs were high. Later, a thermal pressing process using metal moulds was invented. However, the high surface tension of glass caused some detailed parts to be deformed during the pressing process, resulting in unsatisfactory Fresnel lens performance. In addition, the complex manufacturing process and unstable processing accuracy hindered mass production. This resulted in high prices and limited applications for Fresnel lenses. These factors prevented the widespread use of early Fresnel lenses. In contrast, polymer materials offer advantages, such as low density, light weight, high strength-to-weight ratios, and corrosion resistance. They are also cost effective and available in a wide range of grades. Polymer materials have gradually replaced optical glass and other materials in the manufacture of micro-optical lenses and other miniaturised devices. Therefore, this study focuses on investigating the manufacturing parameters of Fresnel lenses in the injection moulding process. We compare the quality of products obtained by two-stage injection moulding, injection compression moulding, and IMD (in-mould decoration) techniques. The results show that the optimal method is IMD, which reduces the nodal displacement on the Fresnel lens surface and improves the transmission performance. To achieve this, we first establish a Kriging model to correlate the process parameters with optimisation objectives, mapping the design parameters and optimisation objectives. Based on the Kriging model, we integrate the NSGA-II algorithm with the predictive model to obtain the Pareto optimal solutions. By analysing the Pareto frontier, we identify the best process parameters. Finally, it is determined that the average nodal displacement on the Fresnel surface is 0.393 mm, at a holding pressure of 320.35 MPa and a melt temperature of 251.40 °C. Combined with IMD technology, product testing shows a transmittance of 95.43% and an optimisation rate of 59.64%. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
38. Performance Analysis of Fresnel Lens Driven Hot Water/Steam Generator for Domestic and Industrial Use: A CFD Research
- Author
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Erdem Cuce and Pinar Mert Cuce
- Subjects
solar collector ,fresnel lens ,steam generator ,domestic hot water ,thermal performance ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
In this study, the design, manufacture and thermal performance analysis of a Fresnel lens driven hot water/steam generator are presented. The designed system is suitable for domestic and industrial hot water/steam usage and can be easily scaled up to meet different capacity needs. In the first step of the research, thermal behaviour of the cast plate heat exchanger driven by a Fresnel lens with a concentration ratio of 100 is investigated at different working fluid velocities (0.6, 0.8, 1.0, 1.5 and 2.0 m/s) and at different absorber surface temperatures (700, 800, 900 and 1000 °C). Outlet temperature of working fluid from the cast plate heat exchanger is determined through a 3D CFD model for each case. The capacity of the steam generator for different operating times (h = 1, 2 and 3 hours) is also evaluated. The highest working fluid temperature at the outlet of heat exchanger is 914.8 °C for T_cp= 1000 °C and V_wf = 0.6 m/s. On the other hand, the lowest temperature is observed as 424.7 °C for T_cp = 700 °C and V_wf = 2.0 m/s. The steam capacity of the system for h = 3 hours is determined as 1696.5 and 508.9 kg in the best (V_wf = 2.0 m/s) and worst cases (V_wf = 0.6 m/s), respectively.
- Published
- 2023
- Full Text
- View/download PDF
39. New solar systems for biodiesel synthesis and other chemical processes: A green and renewable energy to replace conventional energy
- Author
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Khan, Abdul Majeed and Khalil, Rabib
- Published
- 2023
- Full Text
- View/download PDF
40. A Swimming Goggles Optical Design by Fresnel Lenses †.
- Author
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Yeh, Feng-Ming, Huang, Liang-Ying, Chang, Chao-Kai, Hsieh, Ya-Hui, Wang, Hsuan-Fu, Chang, Rong-Seng, and Chen, Der-Chin
- Subjects
MYOPIA ,FRESNEL lenses ,ARTIFICIAL intelligence ,BIG data ,DEEP learning ,DIGITAL technology - Abstract
Currently, many swimming goggle lenses use optical plates to maintain zero refractive power in air and water. However, people's widespread use of 3C products has increased myopia significantly, so lenses have a demand for refractive power. Lenses will have different refractive power problems in water and air media. Therefore, we solved the refractive power change in air and water by using a plane Fresnel lens with a diopter to replace plano-concave lenses. In this study, a first-order design was created and then the microstructure of the Fresnel lens was optimized using optical software. The Fresnel lens simulation results showed that the error was within 5%, which was compared with the data using the lensmaker's equation calculation. For swimming goggles, this error value is tolerable for human vision. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
41. Metamaterial lenses for monostatic and bistatic 77 GHz radar systems.
- Author
-
Kohlberger, Christoph, Hüttner, Richard, Wagner, Christoph, and Stelzer, Andreas
- Subjects
ROAD vehicle radar ,METAMATERIALS ,BISTATIC radar ,FREQUENCY selective surfaces ,RADAR ,ANTENNA feeds - Abstract
Metamaterial lenses are appealing thin alternatives to conventional dielectric lenses. In this contribution we describe their design and application in two exemplary 77 GHz automotive radar sensors operating in monostatic and bistatic modes. The frontends are built around commercially available MMICs and small feed antennas are used in coordination with the six-layer printed circuit board-based realizations of metamaterial lenses. The design follows the principles of dielectric lenses, while the required local phase shift is obtained from a set of metasurface bandpasses. Their design uses a novel interpolation procedure to extract layout parameters for a given phase shift. Despite the small structural sizes due to the high frequency, the fabricated frequency-selective surfaces show very good performance in the required frequency range. Verification measurements were conducted on single bandpasses as well as on metamaterial lenses mounted on the radar frontend. The results agree very well with the simulation and confirm the applicability of thin lenses operating at mm-wave frequencies for automotive radar applications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
42. Fresnel Lens Solar-Pumped Laser with Four Rods and Beam Merging Technique for Uniform and Stable Emission under Tracking Error Influence.
- Author
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Tibúrcio, Bruno D., Liang, Dawei, Almeida, Joana, Garcia, Dário, Catela, Miguel, Costa, Hugo, and Vistas, Cláudia R.
- Subjects
- *
FRESNEL lenses , *LASER pumping , *SOLID-state lasers , *ND-YAG lasers , *SOLAR pumps , *CONTINUOUS wave lasers , *COMPOUND parabolic concentrators - Abstract
Significant numerical improvements in Fresnel lens Nd:YAG solar laser collection efficiency, laser quality factors and tracking error compensation capacity by two Fresnel lenses as primary solar concentrators are reported here. A Nd:YAG four-rod side-pumping configuration was investigated. The four-rod side-pumping scheme consisted of two large aspherical lenses and four semi-cylindrical pump cavities, where the Nd:YAG laser rods were placed, enabling an efficient solar pumping of the laser crystals. A 104.4 W continuous-wave multimode solar laser power was achieved, corresponding to 29.7 W/m2 collection efficiency, which is 1.68 times that of the most efficient experimental Nd:YAG side-pumped solar laser scheme with heliostat–parabolic mirror systems. End-side-pumped configuration has led to the most efficient multimode solar lasers, but it may cause more prejudicial thermal effects, poor beam quality factors and a lack of access to both rod end-faces to optimize the resonant cavity parameters. In the present work, an eight-folding-mirror laser beam merging technique was applied, aiming to attain one laser emission from the four laser rods that consist of the four-rod side-pumping scheme with a higher brightness figure of merit. A 79.8 W multimode laser output power was achieved with this arrangement, corresponding to 22.7 W/m2. The brightness figure of merit was 0.14 W, being 1.6, 21.9 and 15.7 times that of previous experimental Nd:YAG solar lasers pumped by Fresnel lenses. A significant advance in tracking error tolerance was also numerically attained, leading to a 1.5 times enhancement in tracking error width at 10% laser power loss (TEW10%) compared to previous experimental results. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
43. Concentrating behavior of elastic fresnel lens solar concentrator in tensile deformation caused zoom.
- Author
-
Liang, Shen, Ma, Xinglong, He, Qian, Wang, Zhenzhen, and Zheng, Hongfei
- Subjects
- *
SOLAR concentrators , *FOCAL length , *FRESNEL lenses , *COMPOUND parabolic concentrators , *DEFORMATIONS (Mechanics) , *WORKING hours , *ENERGY consumption - Abstract
The focal length of the Fresnel lens changing with the light incident angle will decrease Fresnel lens solar concentrators' energy efficiency and daily working hours, which seriously hinders its commercial application. Existing solutions, mainly including single-axis tracking, two-dimensional tracking, and passive tracking have their limitations and fail to realize the maximum application potential of the Fresnel lens. This paper proposes a novel elastic Fresnel lens solar concentrator, whose focal length can be regulated by tensile deformation. The mechanical and optical coupling simulations are conducted to reveal its concentrating behavior during tensile deformation. An exemplary elastic Fresnel lens with an aperture width of 200 mm and an original focal length of 360 mm is designed and studied. The simulation results illustrate that the optimal base thickness of the elastic Fresnel lens is 1 mm when its prism thickness is 2 mm. Under the optimal thickness parameters combination, the elastic Fresnel lens has an effective elongation rate r about 15%, which increases the focal length by 163 mm and 47% to the original focal length. The focus width only increases from 16 mm to about 20 mm when adjusting the focal length from 360 mm to 523 mm. Besides, the step-zoom strategy increases the exemplified elastic Fresnel lens' acceptable angle from 30° to 45°. The tensile deformation caused zoom method increases the working hours of Fresnel lens by 1.5 times, demonstrating the effectiveness of this method. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
44. Phase-Optimized Multi-Step Phase Acoustic Metasurfaces for Arbitrary Multifocal Beamforming.
- Author
-
Zhao, Jianxin, Wei, Xiongwei, Fei, Chunlong, Li, Yi, Li, Zhaoxi, Lou, Lifei, Quan, Yi, and Yang, Yintang
- Subjects
BEAMFORMING ,TRANSMISSION of sound ,ACOUSTIC imaging - Abstract
Focused ultrasound featuring non-destructive and high sensitivity has attracted widespread attention in biomedical and industrial evaluation. However, most traditional focusing techniques focus on the design and improvement of single-point focusing, neglecting the need to carry more dimensions of multifocal beams. Here we propose an automatic multifocal beamforming method, which is implemented using a four-step phase metasurface. The metasurface composed of four-step phases improves the transmission efficiency of acoustic waves as a matching layer and enhances the focusing efficiency at the target focal position. The change in the number of focused beams does not affect the full width at half maximum (FWHM), revealing the flexibility of the arbitrary multifocal beamforming method. Phase-optimized hybrid lenses reduce the sidelobe amplitude, and excellent agreement is observed between the simulation and experiments for triple-focusing beamforming metasurface lenses. The particle trapping experiment further validates the profile of the triple-focusing beam. The proposed hybrid lens can achieve flexible focusing in three dimensions (3D) and arbitrary multipoint, which may have potential prospects for biomedical imaging, acoustic tweezers, and brain neural modulation. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
45. Seven-Grooved-Rod, Side-Pumping Concept for Highly Efficient TEM 00 -Mode Solar Laser Emission through Fresnel Lenses.
- Author
-
Costa, Hugo, Liang, Dawei, Almeida, Joana, Catela, Miguel, Garcia, Dário, Tibúrcio, Bruno D., and Vistas, Cláudia R.
- Subjects
FRESNEL lenses ,COMPOUND parabolic concentrators ,LASERS ,FUSED silica ,SOLAR energy ,LENSES ,PUMPING machinery - Abstract
Low-cost, lightweight, and easily available Fresnel lenses are a more alluring choice for solar laser power production, when compared to the costly and complex heliostat-parabolic mirror systems. Therefore, a seven-rod solar laser head was designed and numerically studied to enhance the efficiency in TEM
00 -mode laser power production, employing six Fresnel lenses with 10 m2 total collection area for collection and concentration of sunlight. Six folding mirrors redirected the solar rays towards the laser head, composed of six fused silica aspheric lenses and rectangular compound parabolic concentrators paired together for further concentration, and a cylindrical cavity, in which seven Nd:YAG rods were mounted and side-pumped. With conventional rods, total TEM00 -mode laser power reached 139.89 W, which is equivalent to 13.99 W/m2 collection efficiency and 1.47% solar-to-TEM00 -mode laser power conversion efficiency. More importantly, by implementing rods with grooved sidewalls, the total laser power was increased to 153.29 W, corresponding to 15.33 W/m2 collection and 1.61% conversion efficiencies. The side-pumping configuration and the good thermal performance may ensure that the seven-grooved-rod system has better scalability than other previously proposed schemes. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
46. 36‐2: Coarse Integral Imaging Displays with Interleaved Fresnel Lenses.
- Author
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Borjigin, Garimagai and Kakeya, Hideki
- Subjects
FRESNEL lenses ,INTEGRALS ,THREE-dimensional imaging ,PARALLAX - Abstract
This paper realizes coarse integral imaging and coarse integral volumetric imaging displays without seams and moiré, both of which degrade image quality significantly. An integrated interleaved Fresnel lens sheet is used to realize a seamless 3D image with smooth motion parallax, while layered transmissive panels are used to generate a volumetric image without moiré. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
47. Fresnel Lens Solar Pumping for Uniform and Stable Emission of Six Sustainable Laser Beams under Non-Continuous Solar Tracking.
- Author
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Vistas, Cláudia R., Liang, Dawei, Catela, Miguel, Costa, Hugo, Garcia, Dário, Tibúrcio, Bruno D., and Almeida, Joana
- Abstract
A multirod solar laser approach is here proposed to attain uniform and stable multibeam emission under non-continuous solar tracking. A Fresnel lens was used as the primary concentrator. The laser head was composed of a second-stage aspherical lens with a light-guide homogenizer and a third-stage conical pump cavity with six Nd:YAG rods. The solar laser system was optimized through numerical analysis in both Zemax
® and LASCAD™ software to obtain six 1064 nm laser beams of similar multimode power. To investigate the effect of the homogenizer on the laser performance, the laser head was compared with a similar one that only used the aspherical lens in the second stage. The approach with the light guide attained a slightly lower efficiency than the one without the light guide; however, the tracking error width at 10% laser power loss was higher and, most importantly, only a 2.17% coefficient of variation of the laser power emitted by the six rods at the tracking error angle of ±0.5° was obtained. This is 4.2 times better than the 52.31% obtained with the laser head without the homogenizer and 76 times better than that of the previous numerical work. The light guide is thus essential to ensure uniform and stable solar laser power extraction from all rods even under non-continuous solar tracking, making this prototype the ideal for multibeam laser applications where uniformity and stability of the laser power are indispensable. This renewable multibeam solar laser may replace the classical lamp- and diode-pumped lasers, therefore ensuring a sustainable laser power production pattern for both space and terrestrial applications. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
48. Advanced Study of Optical Imaging Systems for Virtual Reality Head-Mounted Displays.
- Author
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Ren, Zhongju, Fu, Xiuhua, Dong, Keyan, Lai, Ying, and Zhang, Jingjing
- Subjects
VIRTUAL reality ,IMAGING systems ,OPTICAL images ,HEAD-mounted displays ,AERONAUTICS education ,DIAGNOSTIC imaging - Abstract
Driven by the rapid innovation of science and technology and industrial manufacturing technology, virtual reality display technology has developed rapidly. At present, the application of virtual reality display technology is expanding in many fields such as military, medical, aviation and education. This paper analyzes the imaging principle of the human vision system and the optical performance requirements of VR heads-up display, summarizes the current design scheme of VR heads-up optical imaging system, focuses on the principle and index parameters of each optical system, and compares the advantages and disadvantages of different schemes. The development prospects and directions of virtual reality headset displays are also prospected. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
49. Optimization of Two Hybrid Micro-Concentrator Photovoltaic Systems for Car-Roof Application
- Author
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El Himer, Sarah, Ouaissa, Mariyam, Ouaissa, Mariya, Kacprzyk, Janusz, Series Editor, El Himer, Sarah, editor, Ouaissa, Mariyam, editor, Emhemed, Abdulrahman A. A., editor, Ouaissa, Mariya, editor, and Boulouard, Zakaria, editor
- Published
- 2022
- Full Text
- View/download PDF
50. Optimum Concentration Ratio for Plastic Optical Fiber-Based Fresnel Lens Daylighting System
- Author
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Kumar, Vikas, Sharma, Karanvir, Bisht, Devendra Singh, Garg, Harry, Jain, V. K., editor, Gomes, Chandima, editor, and Verma, Abhishek, editor
- Published
- 2022
- Full Text
- View/download PDF
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