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- 摘要
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- 实验方案
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[ASME ASME 2018 13th International Manufacturing Science and Engineering Conference - College Station, Texas, USA (Monday 18 June 2018)] Volume 1: Additive Manufacturing; Bio and Sustainable Manufacturing - High-Throughput 3D Printing of Customized Imaging Lenses
摘要： The emerging 3D printing technology has the potential to transform manufacturing customized optical elements, which currently heavily relies on the time-consuming and costly polishing and grinding processes. However, the inherent speed-accuracy trade-off seriously constraints the practical applications of 3D printing technology in optical realm. In addressing this issue, here, we report a new method featuring a significantly faster fabrication speed, at 24.54 mm3/h, without compromising the fabrication accuracy or surface finish required to 3D-print customized optical components. We demonstrated a high-speed 3D printing process with deep subwavelength (sub-10 nm) surface roughness by employing the projection micro-stereolithography process and the synergistic effects from the grayscale photopolymerization and the meniscus equilibrium post-curing methods. Fabricating a customized aspheric lens with 5 mm in height and 3 mm in diameter could be accomplished in less than four hours. The 3D-printed singlet aspheric lens demonstrated a maximal imaging resolution of 2.19 μm with low field distortion less than 0.13% across a 2-mm field of view. This work demonstrates the potential of 3D printing for rapid manufacturing of optical components.
关键词： optical lenses,meniscus equilibrium post-curing,projection micro-stereolithography,3D printing,grayscale photopolymerization
更新于2025-09-23 15:21:01
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A computational model of bio-inspired tunable lenses
摘要： Bio-inspired tunable lenses are composed of soft dielectric elastomer membranes, clear liquids and rigid frames. Being a new type of optical lens, its focus can be adjusted by the applied voltage. For this type of micro-lens to be practically used in real life, the functional relationship between the voltage and the focus needs to be determined, together with the impact of lens parameters such as the pre-stretching of soft dielectric elastomer membranes, the scale and the volume of liquids on this relationship, as well as on the maximum change of lens focus. In this paper, a compact computational model is proposed based on the assumption of homogeneous deformation and application of energy methods. The model results fit well with the experimental data. By using this model, the relationship curve between the applied voltage and the focus has been given, and it has been verified that such lens will not fail in operation. Finally, by analyzing the three parameters of lens, we can also demonstrate that the pre-stretching of dielectric membranes and the scale affect the relationship between the applied voltage and the focus the most, with the volume of liquids having the least impact.
关键词： large deformations,Bio-inspired tunable lenses,dielectric elastomers
更新于2025-09-23 15:21:01
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[ASME ASME 2018 Conference on Smart Materials, Adaptive Structures and Intelligent Systems - San Antonio, Texas, USA (Monday 10 September 2018)] Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies - Manufacture of Lenses and Diffraction Gratings Using DLP As an Additive Manufacturing Technology
摘要： This document condenses the results obtained when 3D printing lenses and their potential use as diffraction gratings using Digital Light Processing (DLP), as an additive manufacturing technique. This project investigated the feasibility of using DLP additive manufacturing for producing custom designed lenses and gratings. DLP was identified as the preferred manufacturing technology for gratings fabrication. Diffraction gratings take advantage of the anisotropy, in additive manufacturing processes, to produce a collated pattern of multiple fringes on a substrate with completely smooth surfaces. The gratings are transmissive and were manufactured with slit separations of 10, 25 and 50 μm. More than 50 samples were printed at various build angles and mechanically treated for maximum optical transparency. The variables of the irradiance equation were obtained from photographs taken with an optical microscope. These values were used to estimate theoretical irradiance patterns of a diffraction grating and compared against the experimental 3-D printed grating. The resulting patterns were found to be remarkably similar in amplitude and distance between peaks when compared to theoretical values.
关键词： 3D printing,lenses,Digital Light Processing (DLP),additive manufacturing,diffraction gratings
更新于2025-09-23 15:21:01
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Double-sided split-step MM-wave Fresnel lenses: design, fabrication and focal field measurements
摘要： Design, fabrication and focal field measurements of W-band Fresnel lenses to produce well-shaped Gaussian beams in the focal domain are presented. Two lenses, one of Teflon and another of Polyamide, have been compared in their performance with a double-sided Fresnel lens of different design, with full height of Fresnel steps. Experiments show that a good focusing ability of all the lenses is achieved. They produce the target beam according to the design. Yet, the lenses of split-step design are thinner, have lower insertion losses, and a greater focal depth as compared to more conventional Fresnel lenses.
关键词： focal fields,Fresnel lenses,Gaussian beam,MM-wave,THz applications
更新于2025-09-23 15:21:01
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ALMOST PERIODIC LUMPED ELEMENTS STRUCTURE MODELING USING ITERATIVE METHOD: APPLICATION TO PHOTONIC JETS AND PLANAR LENSES
摘要： In this work, we show that it is possible to produce a planar electromagnetic jet using a ?at structure consisting of elementary cells based on lumped elements and fed with a source line. A combination of elementary cells may represent a gradient index, locating the electromagnetic energy in a small area, consisting of a few cells and having a size of about 0.75λ. The theoretical framework of the study is based on the Wave Concept Iterative Process method (WCIP) formulated in both spectral and spatial domains. An analogy with an optical model based on optical paths equality enables predicting the location of formation of this spot. The use of such a system can provide solutions for the development of new kinds of applications such as engraving sub-wavelength, data storage, improved scalpel optics for ultra-precise laser surgery, and detection of cancer.
关键词： planar lenses,photonic jets,Wave Concept Iterative Process method,planar electromagnetic jet,lumped elements
更新于2025-09-23 15:21:01
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Artificial pupil versus contralateral balanced contact lens fit for presbyopia correction
摘要： Purpose: To assess and compare the effects of contact lens-based artificial pupil design and contralateral balanced multifocal contact lens combination (CBMCLC) on visual performance. Methods: This randomized crossover study conducted at the University of Valencia, Spain included 38 presbyopic patients using an artificial pupil contact lens in the nondominant eye and a CBMCLC. After a month of lens wear, the binocular distance visual acuity (BDVA), binocular near visual acuity (BNVA), defocus curve, binocular distance, and near contrast sensitivity and near stereoacuity (NSA) were measured under photopic conditions (85 cd/m2). Moreover, BDVA and binocular distance contrast sensitivity were examined under mesopic conditions (5 cd/m2). Results: Visual acuity at an intermediate distance and near vision was better with the CBMCLC than with the artificial pupil (p<0.05). Statistically significant differences were found in contrast sensitivity between the two types of correction for distance (under mesopic conditions) and for near vision, with the CBMCLC exhibiting better results in both cases (p<0.05). The mean NSA values obtained for the artificial pupil contact lens were significantly worse than those for the CBMCLC (p=0.001). Conclusion: The CBMCLC provided greater visual performance in terms of intermediate and near vision compared with the artificial pupil contact lens.
关键词： Prosthesis fitting,Pupil,Presbyopia/rehabilitation,Dominance, ocular,Contact lenses
更新于2025-09-23 15:21:01
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Design and realization of multilayered cylindrical dielectric lens antenna using 3D printing technology
摘要： Herein, design and realization of a novel, low cost, small size, high gain, 3D printed multilayered cylindrical dielectric lens antenna (MLCDLA) is presented at 10 GHz. In the first stage, MLCDLA is designed suitable the 3D printed technology in CST 3D EM simulation environment. Then gain, return loss, and radiation pattern of the design are investigated in the X-band frequencies in the same 3D simulated environment. In the second stage, the designed lens is fabricated by the 3D printed technology in dimensions of 30 × 30 × 52.5 mm3 using acrylonitrile butadiene styrene, with εr = 2.5. In the final stage, performance characteristics of the proposed LCDLA are measured using 10 GHz rectangular waveguide as feeding unit and are compared with the simulated results and counterpart designs in literature. The prototyped MLCDLA is achieved 14 dBi measured gain at 10 GHz. It can be concluded that the proposed 3D printing method not only enables a high performance MLCDLA design but also provides its fast, low cost, and effective prototyping process which can be used for other microwave devices.
关键词： waveguide,novel prototyping methods,dielectric lenses,3D printing
更新于2025-09-19 17:15:36
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Laser-generated focused ultrasound transmitters with frequency-tuned outputs over sub-10-MHz range
摘要： Previous laser-generated focused ultrasound (LGFU) systems have been operated with >15 MHz frequency, allowing for high spatial precision (<100 lm). However, they have been limited only to proximal biomedical applications ex vivo with treatment depths smaller than 10 mm from the lens surface. Although the low-megahertz frequency operation has the advantage of a longer range of therapy, this requires a proper photoacoustic lens made of a nanocomposite coating over a spherically curved substrate whose transmission layer is physically designed for frequency-tuned outputs. This demands a fabrication method that can provide such a nanocomposite structure. We demonstrate photoacoustic lenses operated in an unexplored frequency range of 1–10 MHz, which can simultaneously produce high-amplitude pressure outputs suf?cient for pulsed acoustic cavitation. We physically design a spatially elongated photoacoustic output and then fabricate a transmitter by controlling the density of light-absorbing nanoscale elements in a solution form and by using a replica mold to shape the lens curvature. Our approach is validated by fabricating and characterizing planar transmitters and then applied to focal con?gurations. This offers various possibilities for LGFU-based treatments (e.g., pulsed cavitational therapy such as histotripsy) over the low-megahertz frequency range, which has not been realized by conventional LGFU systems.
关键词： laser-generated focused ultrasound,sub-10-MHz range,frequency-tuned outputs,photoacoustic lenses,acoustic cavitation
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Laser system for recording optics
摘要： The development of a modern laser system for recording optics is presented in this research paper. Studying optical components for designing this system by various methods, by calculated methods and by a method of using modern modeling package Zemax, was conducted. The results of the calculations and simulation, which led to the preliminary design of the laser system of optics registration, coincide.
关键词： lenses,emission,photodiode,laser system,field distribution
更新于2025-09-19 17:13:59
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Practical Chromatic Aberration Correction in Virtual Reality Displays Enabled by Cost‐Effective Ultra‐Broadband Liquid Crystal Polymer Lenses
摘要： Chromatic aberration (CA) is a critical issue in immersive virtual reality displays. The current digital compensation method can reduce the CA by pre-processing the image contents but at the cost of extra memory space, processing time, and power consumption. Moreover, it is not possible to digitally compensate the CA within each color channel. Here, a practical optical approach is presented to correct the CAs, including the sub-channel ones, in the virtual reality system, whose functionality is verified by both ray-tracing analysis and experimental results. In this device, a compact ultra-broadband Pancharatnam-Berry phase lens (PBL) with complex axial molecular structure is fabricated and then hybridized with a refractive Fresnel lens. Due to their opposite chromatic dispersion, the system’s CA is significantly reduced. To eliminate ghost image from the zero-order leakage of PBL, a broadband circular polarizer is implemented to block the stray light. As a result, clear image within the entire 100° field-of-view is achieved. The proposed large-size cost-efficient broadband wide-view flat optics can practically benefit not only virtual reality displays but also general imaging systems for practical applications and scientific research.
关键词： metasurfaces,planar lenses,virtual reality,liquid crystal polymers,chromatic aberration
更新于2025-09-19 17:13:59