Cross-nanofin-based waveplate pixels for broadband hybrid polarization coding in near-field

Abstract As an inherent characteristic of light, polarization plays important roles in information storage, display and even encryption. Metasurfaces, composed of specifically designed subwavelength units in a two-dimensional plane, offer a great convenience for polarization manipulation, yet improving their integrability and broadband fidelity remain significant challenges. Here, based on the combination of various subwavelength cross-nanofins (CNs), a new type of metasurface for multichannel hybrid polarization distribution in near-field is proposed. Sub-wavelength CN units with various waveplate (WP) functionalities, such as frequency-division multiplexing WP, half-WP and quarter-WP are implemented with high efficiency in broadband. High-resolution grayscale image encryption, multi-image storage and rapid polarization detection are demonstrated by encoding the WP pixels into single, double and four channels, respectively. All these applications possess good fidelity in an ultrabroad wavelength band from 1.2 to 1.9 µm, and the high degree of integrability, easy fabrication and multifunction make the CN-shaped WP pixels a promising candidate in optical device miniaturization, quantum applications and imaging technologies.

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The Research and Development of a New Type of Metal Wire-Buckling Machine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.490-495.793 ◽

2012 ◽

Vol 490-495 ◽

pp. 793-796

Author(s):

Yue Hui Liu ◽

Wen Xue Liu ◽

Gen Li Shan

Keyword(s):

Research And Development ◽

High Efficiency ◽

Control Flow ◽

Metal Wire ◽

Compact Structure ◽

Operational Principle ◽

New Type ◽

And Control ◽

High Degree

Designing of a new type of metal wire-buckling machine, introducing the overall structure, operational principle and control flow of the equipment. The machine can realize the feeding, straightening, cutting off, shaping, returning material procedures of the metal wire automatically, with features of high degree of automation, compact structure, good quality and high efficiency.

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Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

Nature Communications ◽

10.1038/s41467-021-24587-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Rohith Mittapally ◽

Byungjun Lee ◽

Linxiao Zhu ◽

Amin Reihani ◽

Ju Won Lim ◽

...

Keyword(s):

Power Density ◽

High Power ◽

High Efficiency ◽

Near Field ◽

Electrical Power ◽

Photovoltaic Cells ◽

High Power Density ◽

Pv Cell ◽

Electrical Power Output ◽

Power Densities

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

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Synthesis, characterization and photocatalytic activity of a new type of high-efficiency polyacid composite

Research on Chemical Intermediates ◽

10.1007/s11164-021-04446-2 ◽

2021 ◽

Author(s):

Chengyu Luan ◽

Qiujie Shan ◽

Peng Wang ◽

Lin Chen ◽

Wei Chen ◽

...

Keyword(s):

Photocatalytic Activity ◽

High Efficiency ◽

New Type

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Design of Multi Standard Near Field Communication Outphasing Transmitter with Modulation Wave Shaping

Electronics ◽

10.3390/electronics10020188 ◽

2021 ◽

Vol 10 (2) ◽

pp. 188

Author(s):

Žiga Korošak ◽

Nejc Suhadolnik ◽

Anton Pleteršek

Keyword(s):

Radio Frequency Identification ◽

High Efficiency ◽

Near Field ◽

Cmos Technology ◽

Near Field Communication ◽

Differential Delay ◽

Fully Differential ◽

Delay Locked Loop ◽

Modulation Wave ◽

The Individual

The aim of this work is to tackle the problem of modulation wave shaping in the field of near field communication (NFC) radio frequency identification (RFID). For this purpose, a high-efficiency transmitter circuit was developed to comply with the strict requirements of the newest EMVCo and NFC Forum specifications for pulse shapes. The proposed circuit uses an outphasing modulator that is based on a digital-to-time converter (DTC). The DTC based outphasing modulator supports amplitude shift keying (ASK) modulation, operates at four times the 13.56 MHz carrier frequency and is made fully differential in order to remove the parasitic phase modulation components. The accompanying transmitter logic includes lookup tables with programmable modulation pulse wave shapes. The modulator solution uses a 64-cell tapped current controlled fully differential delay locked loop (DLL), which produces a 360° delay at 54.24 MHz, and a glitch-free multiplexor to select the individual taps. The outphased output from the modulator is mixed to create an RF pulse width modulated (PWM) output, which drives the antenna. Additionally, this implementation is fully compatible with D-class amplifiers enabling high efficiency. A test circuit of the proposed differential multi-standard reader’s transmitter was simulated in 40 nm CMOS technology. Stricter pulse shape requirements were easily satisfied, while achieving an output linearity of 0.2 bits and maximum power consumption under 7.5 mW.

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Ka-Band Lightweight High-Efficiency Wideband 3D Printed Reflector Antenna

International Journal of Antennas and Propagation ◽

10.1155/2017/7360329 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Yu Zhai ◽

Ding Xu ◽

Yan Zhang

Keyword(s):

High Efficiency ◽

Near Field ◽

Side Lobe ◽

High Gain ◽

Reflector Antenna ◽

Field Analysis ◽

Side Lobe Level ◽

Ka Band ◽

3D Printed ◽

Reflecting Surface

This paper presents a lightweight, cost-efficient, wideband, and high-gain 3D printed parabolic reflector antenna in the Ka-band. A 10 λ reflector is printed with polylactic acid- (PLA-) based material that is a biodegradable type of plastic, preferred in 3D printing. The reflecting surface is made up of multiple stacked layers of copper tape, thick enough to function as a reflecting surface (which is found 4 mm). A conical horn is used for the incident field. A center-fed method has been used to converge the energy in the broadside direction. The proposed antenna results measured a gain of 27.8 dBi, a side lobe level (SLL) of −22 dB, and a maximum of 61.2% aperture efficiency (at 30 GHz). A near-field analysis in terms of amplitude and phase has also been presented which authenticates the accurate spherical to planar wavefront transformation in the scattered field.

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Novel droplet near-field transducer for heat-assisted magnetic recording

Nanophotonics ◽

10.1515/nanoph-2015-0031 ◽

2015 ◽

Vol 4 (4) ◽

pp. 503-510 ◽

Cited By ~ 16

Author(s):

Jacek Gosciniak ◽

Marcus Mooney ◽

Mark Gubbins ◽

Brian Corbett

Keyword(s):

Surface Plasmon ◽

Magnetic Recording ◽

Near Field ◽

Metal Structure ◽

Spot Size ◽

Impedance Match ◽

Localized Surface Plasmon ◽

Heat Assisted Magnetic Recording ◽

Localized Surface Plasmon Resonances ◽

High Degree

AbstractTwo main ingredients of plasmonics are surface plasmon polaritons (SPP) and localized surface plasmon resonances (LSPR) as they provide a high degree of concentration of electromagnetic fields in the vicinity of metal surfaces, which is well beyond that allowed by the diffraction limit of optics. Those properties have been used in the new technique of heat assisted magnetic recording (HAMR) to overcome an existing limit of conventional magnetic recording by utilizing a near-field transducer (NFT). The NFT designs are based on excitation of surface plasmons on a metal structure, which re-radiate with a subdiffraction limited light spot confined in the near field. In this paper, we propose a novel “droplet”-shaped NFT, which takes full advantage of a recenltly proposed Mach–Zehnder Interferometer (MZI), a coupling arrangement that allows optimal coupling of light to the transducer. The droplet design ensures better impedance match with the recording media and, consequently, better coupling of power. The droplet design results in very high enhancement of the electric field and allows the confinement of light in a spot size much smaller than the present stateof- the-art lollipop transducer.

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Hydrogel Sensors for the Agricultural Applications

University of the Future: Re-Imagining Research and Higher Education ◽

10.29117/quarfe.2020.0033 ◽

2020 ◽

Author(s):

Ruba Ali ◽

Tamim Al-Rashid ◽

Youusef Al-Mahmoud ◽

Kishor Kumar

Keyword(s):

Plant Growth ◽

Experimental Work ◽

High Efficiency ◽

Near Field ◽

Soil Porosity ◽

Near Field Communication ◽

Arabic Gum ◽

Communication Device ◽

Agricultural Applications ◽

Control Water

This work is focused on the design and fabrication of hydrogel sensors for the agricultural applications, “a multi-sensory device”. Agriculture is an important contributor to Qatar’s economy, as the country is aiming to produce more local products. We chose to use hydrogel in soil, for their high efficiency in absorbing water. The hydrogel will be embedded in a multisensory device that will provide consistent plant watering when soil is dry and in need for water. The multi-sensory device will employ NFC switch “Near Field Communication” which is a wireless communication device used to control water flow for plant irrigation. Also, the experimental work including enhancing soil properties by using Arabic gum (sodium 2-[(7-carboxyheptyl)-Chydroxycarbonimidoyl] benzen-1-olate), a biodegradable and naturally available polymer. It is proven that it decreases soil porosity, enhances the reinforcement between the soil and the hydrogel therefore retaining more water and preventing evaporation, it also increases plant growth through fixating nitrogen in the soil.

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Autonomous Reaction Network Exploration in Homogeneous and Heterogeneous Catalysis

Topics in Catalysis ◽

10.1007/s11244-021-01543-9 ◽

2022 ◽

Author(s):

Miguel Steiner ◽

Markus Reiher

Keyword(s):

High Efficiency ◽

Reaction Network ◽

Decomposition Reactions ◽

Full Resolution ◽

Manual Inspection ◽

Computational Procedures ◽

Fast Electronic ◽

Processing Errors ◽

High Degree ◽

Computational Catalysis

AbstractAutonomous computations that rely on automated reaction network elucidation algorithms may pave the way to make computational catalysis on a par with experimental research in the field. Several advantages of this approach are key to catalysis: (i) automation allows one to consider orders of magnitude more structures in a systematic and open-ended fashion than what would be accessible by manual inspection. Eventually, full resolution in terms of structural varieties and conformations as well as with respect to the type and number of potentially important elementary reaction steps (including decomposition reactions that determine turnover numbers) may be achieved. (ii) Fast electronic structure methods with uncertainty quantification warrant high efficiency and reliability in order to not only deliver results quickly, but also to allow for predictive work. (iii) A high degree of autonomy reduces the amount of manual human work, processing errors, and human bias. Although being inherently unbiased, it is still steerable with respect to specific regions of an emerging network and with respect to the addition of new reactant species. This allows for a high fidelity of the formalization of some catalytic process and for surprising in silico discoveries. In this work, we first review the state of the art in computational catalysis to embed autonomous explorations into the general field from which it draws its ingredients. We then elaborate on the specific conceptual issues that arise in the context of autonomous computational procedures, some of which we discuss at an example catalytic system. Graphical Abstract

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Comparing Lung Cancer Risks in Sweden, USA, and Japan

ISRN Oncology ◽

10.5402/2012/687298 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Örjan Hallberg ◽

Olle Johansson

Keyword(s):

Lung Cancer ◽

Smoking Prevalence ◽

Risk Function ◽

Cancer Risks ◽

The Usa ◽

New Type ◽

Cancer Rates ◽

Reported Data ◽

High Degree ◽

Smoking Prevalence And Intensity

Objective. To develop a conceptual model for lung cancer rates to describe and quantify observed differences between Sweden and USA contra Japan. Method. A two-parameter lognormal distribution was used to describe the lung cancer rates over time after a 1-year period of smoking. Based on that risk function in combination with smoking prevalence, the calculated age-standardized rates were adjusted to fit reported data from Japan, Sweden, and the USA by parameter variation. Results. The risk of lung cancer is less in Japan than in Sweden and in the USA at the same smoking prevalence and intensity. Calculated age-specific rates did also fit well to reported rates without further parameter adjustments. Conclusions. This new type of cancer model appears to have high degree of predictive value. It is recommended that data from more countries are studied to identify important life-style factors related to lung cancer.

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