scholarly journals Optical Properties of CaF2 Anti-Reflection Coating On ZnS for 8~12 µm Infrared Region

2020 ◽  
Vol 58 (6) ◽  
pp. 433-438
Author(s):  
Ill-Joo Lee ◽  
Seung-Chan Hong ◽  
Byung-Sam Kim ◽  
Jae-Kyung Cheon
Keyword(s):  
Vision System ◽  
Single Layer ◽  
Cost Effective ◽  
Autonomous Driving ◽  
Infrared Region ◽  
Substrate Material ◽  
Night Vision ◽  
High Price ◽  
Thermal Camera ◽  
Quarter Wavelength

Technologies for pedestrian safety are increasingly emphasized by Automakers in advance of autonomous driving vehicles. A Night Vision System attached behind the front grille can reduce fatal accidents, especially during the nighttime, however, consumers may hesitate to adopt such systems on account of their high price. High-cost Germanium is used in commercial Night Vision System windows, and therefore replacing it with a cheaper infrared window material can lead to a more affordable system. To achieve this, Zinc Sulfide (ZnS), which has about 70% transmittance in the Long-Wavelength Infrared region of 8~12 μm, was selected for the window substrate material. In this study, we designed, fabricated and characterized a single layer cost-effective anti-reflection coating on a ZnS window substrate using Calcium Fluoride (CaF2). The CaF2 coating was fabricated by E-beam evaporation technique, with Quarter wavelength anti-reflection thickness (QAR). It was characterized by FT-IR, SEM and a thermal camera test module. We found that CaF2 both side coated the ZnS window and exhibited about 10~15% higher transmittance than the ZnS window substrate. In addition the CaF2 coating stably bonded to the ZnS substrate without any internal defects. A thermal camera based window test also showed better detection performance with the CaF2 Coating than a bare ZnS substrate window, which was calculated using the output voltage of the microbolometer thermal sensor.

scholarly journals A single layer deposition of Li-doped mesoporous TiO2 beads for low-cost and efficient dye-sensitized solar cells

2021 ◽  
Vol 45 (5) ◽  
pp. 2470-2477
Author(s):  
P. Golvari ◽  
E. Nouri ◽  
N. Mohsenzadegan ◽  
M. R. Mohammadi ◽  
S. O. Martinez-Chapa
Keyword(s):  
Light Scattering ◽  
Low Cost ◽  
Dye Sensitized Solar Cells ◽  
Single Layer ◽  
Cost Effective ◽  
Mesoporous Tio2 ◽  
Trap States ◽  
Dye Sensitized ◽  
Layer Deposition ◽  
Sensitized Solar Cells

Cost-effective DSCs with superior electronic properties are gained by a reduction in electronic trap states and outstanding light scattering and harvesting.

scholarly journals Spectroscopic detection of forest diseases: a review (1970–2020)

2021 ◽  
Author(s):  
Lorenzo Cotrozzi
Keyword(s):  
Early Detection ◽  
Optical Sensors ◽  
Near Infrared ◽  
Sustainable Forest Management ◽  
Visible Spectrum ◽  
Cost Effective ◽  
Infrared Region ◽  
Forest Disturbances ◽  
Effective Manner ◽  
Forest Diseases

AbstractSustainable forest management is essential to confront the detrimental impacts of diseases on forest ecosystems. This review highlights the potential of vegetation spectroscopy in improving the feasibility of assessing forest disturbances induced by diseases in a timely and cost-effective manner. The basic concepts of vegetation spectroscopy and its application in phytopathology are first outlined then the literature on the topic is discussed. Using several optical sensors from leaf to landscape-level, a number of forest diseases characterized by variable pathogenic processes have been detected, identified and quantified in many country sites worldwide. Overall, these reviewed studies have pointed out the green and red regions of the visible spectrum, the red-edge and the early near-infrared as the spectral regions most sensitive to the disease development as they are mostly related to chlorophyll changes and symptom development. Late disease conditions particularly affect the shortwave-infrared region, mostly related to water content. This review also highlights some major issues to be addressed such as the need to explore other major forest diseases and geographic areas, to further develop hyperspectral sensors for early detection and discrimination of forest disturbances, to improve devices for remote sensing, to implement long-term monitoring, and to advance algorithms for exploitation of spectral data. Achieving of these goals will enhance the capability of vegetation spectroscopy in early detection of forest stress and in managing forest diseases.

scholarly journals Nanoprinted high-neuron-density optical linear perceptrons performing near-infrared inference on a CMOS chip

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Elena Goi ◽  
Xi Chen ◽  
Qiming Zhang ◽  
Benjamin P. Cumming ◽  
Steffen Schoenhardt ◽  
...  
Keyword(s):  
Machine Learning ◽  
High Speed ◽  
Near Infrared ◽  
Single Layer ◽  
Infrared Region ◽  
Optical Devices ◽  
Medical Diagnostics ◽  
Oxide Semiconductor ◽  
Process Data ◽  
Neuron Density

AbstractOptical machine learning has emerged as an important research area that, by leveraging the advantages inherent to optical signals, such as parallelism and high speed, paves the way for a future where optical hardware can process data at the speed of light. In this work, we present such optical devices for data processing in the form of single-layer nanoscale holographic perceptrons trained to perform optical inference tasks. We experimentally show the functionality of these passive optical devices in the example of decryptors trained to perform optical inference of single or whole classes of keys through symmetric and asymmetric decryption. The decryptors, designed for operation in the near-infrared region, are nanoprinted on complementary metal-oxide–semiconductor chips by galvo-dithered two-photon nanolithography with axial nanostepping of 10 nm1,2, achieving a neuron density of >500 million neurons per square centimetre. This power-efficient commixture of machine learning and on-chip integration may have a transformative impact on optical decryption3, sensing4, medical diagnostics5 and computing6,7.

Novel investigation on tribological behavior of microwave synthesized functionally graded claddings

2021 ◽  
pp. 095440622110458
Author(s):  
Sarbjeet Kaushal ◽  
Dheeraj Gupta ◽  
Hiralal Bhowmick
Keyword(s):  
Functional Performance ◽  
Single Layer ◽  
Substrate Material ◽  
Functionally Graded ◽  
Dry Sliding Wear ◽  
Wear Loss ◽  
Dry Sliding ◽  
Maximum Value ◽  
Microhardness Profile ◽  
Pin On Disk

In this study, functional performance of Ni/Cr3C2 functionally graded claddings (FGCs) was investigated under dry sliding wear environment. The Ni/Cr3C2-based FGCs were produced by varying Cr3C2 fraction (Ni-XCr3C2) (X=10%–30% by weight) using microwave irradiation. The FGC layers were composed of cellular-structure with reinforced particles dispersed randomly inside Ni-based matrix. Variation of Cr3C2 particles inside Ni matrix exhibited significant impact on micro-structural and mechanical properties. The microhardness profile of the FGC layers showed an increase in hardness value with an increase in the amount of reinforced Cr3C2 particles. FGC top layers showed the maximum value of micro-hardness of 555 ± 34 HV. Functional performance of microwave processed FGCs was studied through the pin-on-disk tribometer under varying sliding velocity and sliding distances. For comprehension study, wear study was also carried out on microwave processed single layer clads with compositions corresponding to FGC layers. The FGC sample showed better wear resistance than all single clad layers and substrate material. The FGC sample exhibited 1.6 times less wear rate than the Ni-based + 30% Cr3C2 single layer clad. The worn-out surfaces of FGC and single-layer-clads showed presence of multiples cracks and grooves, which resulted in their weight loss during dry sliding contact. Material debonding and the formation of craters and cracks are the main phenomena responsible for the wear loss in the FGC surface.

scholarly journals A Study on the Development of Night Vision Thermal Camera Using Deep Learning

2019 ◽  
Vol 44 (12) ◽  
pp. 2332-2338
Author(s):  
Woong Hwang ◽  
Sang Been Oh ◽  
Yoon Joo Nam ◽  
Soonghwan Ro
Keyword(s):  
Deep Learning ◽  
Night Vision ◽  
Thermal Camera

scholarly journals Development and Students’ Perception on Teaching Aids of Photoelectric Effect Experiment Using Leds

2019 ◽  
Vol 7 (3) ◽  
pp. 253-261
Author(s):  
Hartono Bancong ◽  
Ana Dhiqfaini Sultan ◽  
Subaer Subaer ◽  
Muris Muris
Keyword(s):  
Cost Effective ◽  
Photoelectric Effect ◽  
High Price ◽  
Planck’S Constant ◽  
Teaching Aids ◽  
Modern Physics ◽  
User Friendly ◽  
Planck's Constant ◽  
D Model ◽  
Effect Experiment

The photoelectric effect experiment generally uses a very sophisticated and expensive apparatus. Some high schools and even universities in Indonesia cannot afford to conduct this experiment because of the high price of the apparatus. The purpose of this study was to develop a user-friendly, and cost-effective teaching aids which can be used to demonstrate the concepts of modern physics related to the photoelectric effect. The stages of this study employed the Four-D model, namely define, design, develop, and disseminate. Based on experts and practitioner evaluation, the developed teaching aids and practicum devices of photoelectric effect experiment were found to be valid and reliable. The results of the experiment by using this developed teaching aids of the photoelectric effect showed that there is a linear relationship between the stopping potential and the frequency of light emitted by the LED. These results are consistent with Millikan's experimental results, the first physicist who succeed in proving Einstein's hypothesis of the photoelectric effect, that in the photoelectric effect the stopping potential does not depend on the intensity of light but depends only on the frequency of light. In this study, the Planck’s constant value obtained is 6.408x10-34 J.s. Although this value is slightly smaller than the accepted value of Planck's constant that is 6.626x10-34 J.s, it is good enough considering the instrumental error occurred during the measurement of current and voltage. Furthermore, the students’ perception of the developed teaching aids and practicum devices of the photoelectric effects experiment are 74.9% (good) and 80.2% (very good), respectively. This indicates that the photoelectric effect experiment teaching aids and practicum devices that have been developed can be used to demonstrate and prove the concepts of modern physics related to the photoelectric phenomena correctly.Keywords: Teaching Aids, Photoelectric Effect, Students’ Perception

scholarly journals Expand bandwidth high reflectivity of the far infrared region

2005 ◽  
Vol 2 (1) ◽  
pp. 65-69
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Far Infrared ◽  
Infrared Region ◽  
High Reflectivity ◽  
Quarter Wavelength ◽  
Multilayer Materials

Was expanded display high reflectivity of the spectral remote infrared (m j 14-8) adoption order Alcolmtin ????????? thickness optical northeastern quarter wavelength and compared with results of previous studies based Aldrashalhalah on Ndharah matrix distinctive amended and fall of light close to the vertical arrangement multilayer materials buffer and in thin films homogeneous and uniform properties deposited on germanium basis results showed that the best choice for governments and their kills to expand bandwidth high reflectivity is much easier for the infrared than the area visible in addition to the order of these stacks is the cornerstone of the filters other visual...

Performance Analysis of a LTE Band Microstrip Antenna on FR-4 Material

2014 ◽  
Vol 974 ◽  
pp. 215-219
Author(s):  
Afaz Uddin Ahmed ◽  
Rezaul Azim ◽  
Tariqul Islam Mohammad ◽  
Mahamod Ismail ◽  
Md. Shabiul Islam
Keyword(s):  
Performance Analysis ◽  
Microstrip Antenna ◽  
Material Selection ◽  
Cost Effective ◽  
Substrate Material ◽  
Rectangular Slot ◽  
S Parameter ◽  
Cost Effective Approach ◽  
Term Evaluation ◽  
Resin Binder

This paper presents the performance analysis of a LTE (Long Term Evaluation) band microstrip antenna printed on FR-4 substrate material. FR-4 substrate is a composite material of fiberglass cloth with flame resistive epoxy resin binder. It is a popular candidate for material selection in antenna design at higher bands. The proposed antenna contains a rectangular slot on the patch and covers the LTE band 7 (2.5 - 2.7 GHz). It is a cost effective approach to fabricate microstrip antenna for the LTE band 7 which is used in LTE technology throughout the world. The result shows a coverage bandwidth (<-6 dB) from 2.47 GHz – to 2.75 GHz and at 2.6 GHz the maximum achieved gain is 5.2 dB. The S-parameter is used as a comparison matrix for the simulated and fabricated antennas.

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