An ultrashort throw lens with a catadioptric relay (USTCR) for curved screens has a half-field angle greater than 110 degrees. The angle of the principal ray incident on the aspherical mirror increases according to th...
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ISBN:
(数字)9781510644670
ISBN:
(纸本)9781510644670
An ultrashort throw lens with a catadioptric relay (USTCR) for curved screens has a half-field angle greater than 110 degrees. The angle of the principal ray incident on the aspherical mirror increases according to the height of the ray emitted from the object surface. A larger field angle leads to larger sag amount. Thus, the degree of difficulty in precision machining increases. In this study, we examined how the tangent of the concave mirror surface can be reduced such that it can be manufactured while maintaining the half-field angle and its optical performance. It was found that the interval between imaging points reaching the screen can be made constant by suppressing the change in the principal ray incident on the concave mirror by +1- 1 degrees or less, particularly in the area of a half-field angle of 90 degrees or more, and making the change in the tangent of the concave mirror surface constant. As an index of distortion, we show that the perimeter ratio (Pr) of the frame length, which was equally divided by 5 x5 in the screen, improved from 0.26 to 0.73. As one possible application, a projection system that can be realized with only 8 projectors is proposed, as opposed to conventional systems consisting of approximately 20 projectors in omni-directional projection systems.
We demonstrate an iterative and inverse design of a segmented reflector used to illuminate the road with a uniform light distribution and reduced glare to the oncoming traffic. design is set to meet the StVZO standard...
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ISBN:
(数字)9781510644670
ISBN:
(纸本)9781510644670
We demonstrate an iterative and inverse design of a segmented reflector used to illuminate the road with a uniform light distribution and reduced glare to the oncoming traffic. design is set to meet the StVZO standard. The maximum brightness obtained is 1460 candela, which is five times brighter than a conventional headlamp of urban shared electric scooters and bicycles, resulting in improved visibility in dark environments. A prototype was built and tested at various environments. The tolerance analysis showed no negative influence on the desired standard light distribution. In addition to this iterative approach, a ray tracing code has been developed for inverse design and to map a desired uniform road illumination pattern back to the candela sensor for corresponding reflector design.
The design, development, and experimental validation of an inductively-powered four-channel optical neurostimulator system on a chip (SoC) with on-chip neural recording, temperature monitoring, signal processing, and ...
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The design, development, and experimental validation of an inductively-powered four-channel optical neurostimulator system on a chip (SoC) with on-chip neural recording, temperature monitoring, signal processing, and bidirectional wireless data communication are presented. Abiologically-inspired optical stimulation approach is employed that extends the limitations on the stimulation pulse-width and frequency (i.e., enabling wirelessly-powered optical stimulation at very lowfrequencies (e.g., <10 Hz)) while significantly reducing the required on-device storage capacitor size. The biological efficacy of the proposed approach is validated and compared with conventional stimulation through in vitro experiments. The stimulator's energy efficiency is enhanced by employing a high-gain (850 A/A) current amplifier/driver in each channel that steers up to 10 mA into the optical source with an excellent linearity (vertical bar INL vertical bar <0.5LSB), while 1) yielding the lowest-in-literature required voltage headroom, and 2) being insensitive to large (up to 12%) supply voltage drops, which is ideal for battery-less implantable devices. Additionally, to maximize the percentage of the generated optical power that reaches the targeted cells (thus, further energy efficiency enhancement), inkjet printing is utilized to fabricate custom-designed optical mu lenses that are placed directly on top of the silicon SoC to enhance the generated light's directivity by >30x. An electrophysiological recording channel for real-time monitoring of the stimulation efficacy and a high-precision (0.1. C resolution) temperature readout circuit for shutting off stimulation upon detection of an unsafe temperature increase are also integrated on the chip. Additionally, the SoC hosts an ASK receiver and an LSK transmitter for downlink and uplink wireless data communication, respectively. The SoC is fabricated in a standard 130 nm CMOS process and occupies 6 mm(2). Measurement results for different
We applied an extended version of the Niching-CMA-ES heuristic to search for local minima of the Cooke triplet, a renowned photographic lensdesign, of which 21 local minima were already known. The considered problem ...
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ISBN:
(数字)9781510644670
ISBN:
(纸本)9781510644670
We applied an extended version of the Niching-CMA-ES heuristic to search for local minima of the Cooke triplet, a renowned photographic lensdesign, of which 21 local minima were already known. The considered problem is defined by 6 input (decision) variables, namely the curvatures of the three lenses present in the Cooke triplet, and is driven by a single objective function, that is the RMS spot size. The applied approach found: (i) 19 out of the 21 known minima in a single run;(ii) 540 new local minima with objective values lower/equal to those of the known 21 minima;(iii) a large number of infeasible designs.
Active optical components are essential building blocks for a wide variety of applications such as optical communications, microscopy, and illumination systems. Reconfigurable metasurfaces, which consist of arrays of ...
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ISBN:
(数字)9781510644670
ISBN:
(纸本)9781510644670
Active optical components are essential building blocks for a wide variety of applications such as optical communications, microscopy, and illumination systems. Reconfigurable metasurfaces, which consist of arrays of sub-wavelength meta-atoms, can be engineered to uniquely realize compact and multifunctional optical elements, enabling light-polarization dynamic-control as well as beam steering, focusing or zooming. Varifocal metalenses, in particular, have attracted increasing interests. Yet, going beyond mechanical modulation schemes to realize ultra-thin devices with fast modulation remains challenging due to the complex phase and phase-delay profiles involved. Recently, thermooptical effects in dielectric nanostructures have emerged as a promising solution to tune their optical resonances, offering unexplored opportunities for ultra-thin reconfigurable metalenses, in particular silicon based ones. In this work, we report a proof-of-concept design of an ultrathin (300 nm thick) and thermo-optically reconfigurable silicon metalens operating in the visible regime (632 nm). Importantly, we demonstrate that, using thermo-optical effects, it is possible to achieve continuous modulation of the focal-length at a fixed wavelength. In particular, operating under right-circularly polarized light, our metalens exhibits a linear focal shift from 165 mu m at 20 degrees C to 135 mu m at 260 degrees C, exceeding the lens focal depth. The average conversion efficiency of the lens is 26%, close to mechanically modulated devices, while its Strehl ratio is 0.99, confirming a diffraction-limited performance. Concurrently, in this work we report an automatized methodology to design a reconfigurable metalens, compute its layout and verify the expected performance. Overall, we envision that, by further optimization of the optical response of individual meta-atoms with machine-learning algorithms, thermally-reconfigurable silicon metalenses will emerge as a viable, chip-compatible soluti
The Integrated Green-Grey-Blue System (IGGBS) represents an advanced strategy for sustainable stormwater management, critically enhancing water resource efficiency and urban resilience. This study utilizes the Web of ...
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The frequency range of terahertz (THz) has shown great promise for optical communication due to its enormous bandwidth and low interference. This review paper provides a thorough analysis of the latest developments an...
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ISBN:
(数字)9798331528126
ISBN:
(纸本)9798331528133
The frequency range of terahertz (THz) has shown great promise for optical communication due to its enormous bandwidth and low interference. This review paper provides a thorough analysis of the latest developments and current obstacles in THz optical *** microwave and infrared wavelengths, the terahertz (THz) frequency range has special possibilities for optical communication *** investigates how THz frequencies and optical communication are convergent, emphasising the latter's promise for high-bandwidth, low-latency data transfer. We investigate possible uses of THz optical communication, such as sensing, imaging, and wireless networks, highlighting the revolutionary influence of this new sector on the design of communication systems in the future.
The proceedings contain 40 papers. The special focus in this conference is on Advances in Metrology. The topics include: Calibration of Pentaprism and Its Uncertainty Evaluation at NPL, India;Fuzzy-Based MPPT Controll...
ISBN:
(纸本)9789811924675
The proceedings contain 40 papers. The special focus in this conference is on Advances in Metrology. The topics include: Calibration of Pentaprism and Its Uncertainty Evaluation at NPL, India;Fuzzy-Based MPPT Controlled 3Z Boost Converter for PV Applications;Real-Time Realization and Validation of LabVIEW-Based Automation Program for AC–DC Voltage and current Measurements of AC Calibrators;Biomedical Signal Processing: ECG Signal Analysis Using Machine Learning in MATLAB;Study of DC Sputtered Undoped NiO Thin Films;a Review on Sources of Uncertainty in Thermal Conductivity Measurement for Thermal Transport Metrology;error Analysis in Measurement of Electrical Conductivity;errors in Measurement of Magnetic Field and Magnetic Moment with its Associated Uncertainty;generation of Tunable Perfect Vortex Beam by Varying Focus of Axicon-lens Assembly;uncertainty Evaluation Through Monte Carlo Simulation for Flatness Measurement of optical Flats;A Brief Discussion on GMR and TMR Effect and Importance of Metrology for Accurate Measurements of Its Parameters;Indian Standard Time Synchronization Via NTP Server Over Different Networks;Recent developments in Surface Acoustic Wave (SAW) Sensors and Their Applications in Different Areas;An Adaptive Color Image Watermarking Scheme Using Combination of PSO-LTSVR in Wavelet Domain for Copyright Protection;study of Electromagnetic Induced Transparency and Its Dependence on Probe Decay for Cascade and Lambda Models;reliability Measurement of Complex Industrial Redundant systems Using Semi-Markov Process and Regenerative Point Technique;comparison of Different Feature Selection Approaches on Breast Cancer Dataset;double-Layer Secured Automatic Home Access System with Gas Detector Sensor Using Raspberry Pi and Python;Electrical Properties of PU/CdS Nanocomposites.
We introduce a closed-form formula to design a spherochromatic collimator singlet lens. The light for three different wavelengths is collimated at the output of the lens. We test the singlet lens using ray-tracing met...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
We introduce a closed-form formula to design a spherochromatic collimator singlet lens. The light for three different wavelengths is collimated at the output of the lens. We test the singlet lens using ray-tracing methods and we find satisfactory results for three different wavelengths.
We derive a closed-form expression for the entrance pupil of the on-axis stigmatic singlet lens, and discuss its performance for a variety of conditions, including positive or negative indices of refraction, and diffe...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
We derive a closed-form expression for the entrance pupil of the on-axis stigmatic singlet lens, and discuss its performance for a variety of conditions, including positive or negative indices of refraction, and different positions of the object and the image.
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