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- 2019
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- infrared image
- target detection
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- Infrared camera
- Eye movement
- Optoelectronic Information Science and Engineering
- Chinese Academy of Sciences
- Gunma University
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- Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Science
- University of Science and Technology of China
- Space Star Technology Co. LTD
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First vibrational investigations of N <sub/>2</sub> O–H <sub/>2</sub> O, N <sub/>2</sub> O–(H <sub/>2</sub> O) <sub/>2</sub> , and (N <sub/>2</sub> O) <sub/>2</sub> –H <sub/>2</sub> O complexes from the far to the near-infrared spectral region by neon matrix isolation and <i>ab initio</i> calculations
摘要： We present for the first time the investigation of water molecules complexed with dinitrogen monoxide, two abundant molecules in atmosphere, in solid neon using Fourier transform infrared (IR) spectroscopy. We identify at least three complexes from concentration effects, N2O–H2O, N2O–(H2O)2, and (N2O)2–H2O, by observation of new absorption bands close to the monomer fundamental modes from the far to the near IR region. We highlight the presence of isomers for the N2O–H2O complex with the help of theoretical calculations at second order M?ller-Plesset (MP2) and coupled-cluster single double triple-F12a/aug-cc-pVTZ levels. The observed frequencies for the N2O–(H2O)2 and (N2O)2–H2O complexes are compared with MP2/aug-cc-pVTZ harmonic data. Anharmonic coupling constants have been derived from the observations of overtones and combination bands.
关键词： ab initio calculations,anharmonic coupling constants,neon matrix isolation,N2O–H2O complexes,Fourier transform infrared spectroscopy
更新于2025-09-09 09:28:46
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[IEEE 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz2018) - Nagoya, Japan (2018.9.9-2018.9.14)] 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Far Infrared and THz Detectors: Principles of Operation and Figures of Merit
摘要： In this paper we discuss characteristics of detectors and their experimental applications in the Far Infared (FIR) and lower THz spectral range: 50-3000 GHz (6mm-100 μm), with special attention to Plasma Diagnostics, THz-TDS and Free Electron Lasers (FEL). The International System of Units (SI) will be used throughout.
关键词： THz-TDS,Far Infrared,THz Detectors,Plasma Diagnostics,Free Electron Lasers
更新于2025-09-09 09:28:46
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Temperature Compensation on Sugar Content Prediction of Molasses by Near-Infrared Spectroscopy (NIR)
摘要： The rapid, nondestructive, cost-effective NIR measurement method was used for final molasses quality monitoring to determine fermentable sugar content to optimize ethanol yield. Molasses is stored in temperature-controlled tanks during the cane crushing and remelt seasons to ensure molasses quality and availability. However, there is variation in molasses temperature during storage. The impacts of temperature variation on molasses NIR spectra and calibration performance were studied. About one hundred molasses samples were collected for spectral profiling (400–2500 nm) at three different temperatures (25, 35 and 45 °C) using a FOSS NIR DS2500 spectrometer. A partial least squares regression (PLSR) model was developed using full cross-validation. The predictive models were developed using molasses spectra at 25, 35 and 45 °C and used to determine sucrose, glucose, fructose (fermentable sugars) concentrations in the molasses. External validation was achieved using thirty percent of calibration samples for each validation set, 25, 35, and 45 °C. Variation of the sample spectra was observed for the visible region and NIR region (1450 and 1970 nm), due to O–H bonding. The root means squared standard error of cross-validation obtained varied depending on sample temperature. Root means squared standard error of prediction results for external validation samples tended to increase with increasing temperature. Predicted values were not statistically different (p > 0.05) to reference values using different temperatures of models and validation. Calibration models including three temperature spectra showed potential of fermentable sugar analysis in molasses without temperature compensation.
关键词： Molasses,Non-destructive,Temperature compensation,Rapid,Near Infrared Spectroscopy
更新于2025-09-09 09:28:46
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Preparation and protection of ZnS surface sub-wavelength structure for infrared window
摘要： Zinc sulfide (ZnS) is one of the most important far-infrared optical candidate materials. However, it is indispensable for ZnS to improve its antireflection and protection especially under harsh environments. Compared with conventional surface antireflective films, surface sub-wavelength structures (SWSs) have some unique advantages. In this paper, dewetting nickel dots as etching mask on ZnS substrates were obtained by thermal annealing of as-sputtered Ni films on the intermediate layers of as-sputtered silicon films. ZnS SWSs were then prepared by inductively coupled plasma (ICP) etching. Finally, HfO2 films were deposited on ZnS SWSs by atomic layer deposition. The influences of SWSs and ALD-derived HfO2 films on the transmittance and protection of ZnS were both investigated. The experimental results show that ZnS SWSs can increase both far-infrared transmittance and surface hydrophobicity. Meanwhile, ALD-derived HfO2 films can provide good protection. Compared with bare ZnS, HfO2-coated ZnS with double-sided SWS exhibits average transmittance of 79.2% other than initial 69.1% in 8–12 μm, better hydrophobicity with the wetting angle of 119.7°, and higher composite nano-hardness increased from 25.00 to 38.68 GPa. ALD derived HfO2 films on ZnS surface sub-wavelength structures have excellent application prospective for infrared optical windows.
关键词： Subwavelength structure,Antireflection,Infrared window,ZnS,Protection
更新于2025-09-09 09:28:46
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Antimonide Based Infrared Detectors for Remote Sensing
摘要： Infrared imaging (3‐25 microns) has been an important technological tool for the past 60 years since the first report of infrared detectors in 1950s. There has been a dramatic progress in the development of antimonide based detectors and low power electronic devices in the past decade with new materials like InAsSb, InAs/GaSb superlattices and InAs/InAsSb superlattices demonstrating very good performance. One of the unique aspects of the 6.1A family of semiconductors (InAs, GaSb and AlSb) is the ability to engineer the bandstructure to obtain designer band‐offsets. Our group investigates fundamental challenges in antimonide based infrared detectors and explores new avenues for next generation infrared detectors, arrays and imagers. The proposed technology has relevance for active and passive imaging for remote sensing applications. In this presentation, I will describe the material science and device physics of the antimonide systems. I will also discuss the challenges in these systems including the identification of defects that limit the performance of the detector. The use of 'unipolar barrier engineering' to realize high performance infrared detectors and focal plane arrays will be discussed. We are currently investigating low excess noise avalanche photodiodes (APDs) using superlattices. This has very important applications in remote sensing as there are two essential trade offs. The first is the conventional speed‐sensitivity trade off that limits the gain‐bandwidth product and the user has to decide the appropriate detector that meets their system requirement. The other trade‐off relates the sensitivity with the dynamic range. Researchers have used elegant approaches with the use of two detectors to achieve a high sensitivity and large dynamic range.
关键词： antimonide,remote sensing,superlattices,infrared detectors,avalanche photodiodes
更新于2025-09-09 09:28:46
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Infrared thermography camera protection in dairy farming management
摘要： Infrared thermography as a non-invasive contactless method of temperature distribution is ideal for various types of analyses. Thermal cameras have some protection against direct sprays of water and dust but no deposit on a camera is allowed. Educated camera operators often find themselves in situations where they have to conduct an analysis during which the equipment is exposed to unforeseen working conditions. One such occasion is dairy farming management. Analyzing dairy cows with a thermal camera exposes expensive equipment to faeces and urine. Camera protection is normally carried out by the usage of a thermal window, protective lens or special housing. One of the materials used in lens protection manufacturing is polyethylene used to make plastic bags. The paper elaborates on camera protection in order to support the usage of a plastic bag for camera protection when in unexpected circumstances. Two experiments were performed under controlled conditions and one in real conditions on a dairy farm with and without the usage of a plastic bag. The impact of the bag and its thickness on the results of thermographic analysis of a homogeneous radiation source at ambient temperature did not provide desired information due to thermal equilibrium. The setup analysis with a heat source that have the same temperature difference as a real cow in the farm has shown the influence of bag thickness as well as a different setup on the camera. The importance of a bag being well stretched over the camera lens in order to get homogeneous and minimal influence on the final measurement results was emphasized prior to the final shooting in the farm condition. In the dairy cow analysis, when the plastic bag was mounted over the camera, the temperature difference was observed. It was shown that the difference increases alongside with the increase of the observed object temperature. The plastic bag reduces the registered cow apparent temperature but similarly raises the ambient temperature.
关键词： Infrared thermography,Farm,Dairy cow,Equipment protection,Plastic bag
更新于2025-09-09 09:28:46
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Near-infrared photodetection with plasmon-induced hot electrons using silicon nanopillar array structure
摘要： A plasmon-induced hot-electron photodetector based on silicon nanopillar array is developed. The nanostructure is fabricated by reactive ion etching with a monolayer of self-assembled polystyrene nanosphere in hexagonal close-packed lattice as the mask. Light absorption and hot-electron generation are mainly enhanced by the surface plasmon polaritons formed at the surface of the gold film on the nanopillar sidewalls. The photoresponse spans two telecom wavebands, viz. the range of 1250-1600 nm, and has a value of 2.5 mA/W at 1310 nm. The proposed silicon nanopillar-based hot-electron infrared detector has great potentials for device integration in silicon photonics relying on the economic large-area fabrication process.
关键词： near-infrared photodetector,Schottky diode,hot electrons,nanopillar
更新于2025-09-09 09:28:46
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Portable Mid-Infrared Device and Chemometrics for the Prediction of Low (0.5%) Total <i>Trans</i> Fat Content in Fast Foods
摘要： The ruling that partially hydrogenated oils (PHO) are no longer “generally recognized as safe (GRAS),” has accelerated the replacement of PHO ingredients with fat alternatives having increasingly lower or no trans fat content. In the present study, we developed a Fourier-transform infrared (FTIR) spectroscopic procedure in conjunction with multivariate partial least squares regression (PLSR) and found it suitable for the accurate prediction of low (0.5%) total trans fat content, as percentage of total fat, measured as fatty acid methyl esters (FAME), in the lipids extracted from 24 representative fast foods. This multivariate data analysis approach is relevant because the precision of the current univariate FTIR official method (AOCS Cd 14-09) is reportedly poor below 2% of total fat, while PLSR has allowed us to accurately predict the concentration of low trans fat in fast foods. The performance of a portable FTIR device was also evaluated and compared to that of a benchtop FTIR spectrometer. For both infrared data sets, PLSR-predicted concentrations of total trans FAME, ranging from approximately 0.47% to 11.40% of total FAME, were in good agreement with those determined by a primary reference gas chromatography (GC) method (R2>0.99); high prediction accuracy was also evidenced by low root mean square error of cross-validation (RMSECV) values. The lowest RMSECV error of 0.12% was obtained with the portable device. The lowest total trans FAME concentration, determined by GC to be 0.42%, was accurately predicted by the portable FTIR/PLSR procedure as 0.47% of total FAME.
关键词： partial least squares regression,portable device,infrared spectroscopy,low trans fat content,fast foods
更新于2025-09-09 09:28:46
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An NIR-II Fluorescence/Dual Bioluminescence Multiplexed Imaging for In Vivo Visualizing the Location, Survival, and Differentiation of Transplanted Stem Cells
摘要： The in vivo distribution, viability, and differentiation capability of transplanted stem cells are vital for the therapeutic efficacy of stem cell–based therapy. Herein, an NIR-II fluorescence/dual bioluminescence multiplexed imaging method covering the visible and the second near-infrared window from 400 to 1700 nm is successfully developed for in vivo monitoring the location, survival, and osteogenic differentiation of transplanted human mesenchymal stem cells (hMSCs) in a calvarial defect mouse model. The exogenous Ag2S quantum dot–based fluorescence imaging in the second near-infrared window is applied for visualizing the long-term biodistribution of transplanted hMSCs. Endogenous red firefly luciferase (RFLuc)-based bioluminescence imaging (BLI) and the collagen type 1 promoter–driven Gaussia luciferase (GLuc)-based BLI are employed to report the survival and osteogenic differentiation statuses of the transplanted hMSCs. Meanwhile, by integrating the three imaging channels, multiple dynamic biological behaviors of transplanted hMSCs and the promotion effects of immunosuppression and the bone morphogenetic protein 2 on the survival and osteogenic differentiation of transplanted hMSCs are directly observed. The novel multiplexed imaging method can greatly expand the capability for multifunctional analysis of the fates and therapeutic capabilities of the transplanted stem cells, and aid in the improvement of stem cell–based regeneration therapies and their clinical translation.
关键词： near-infrared fluorescence imaging,bioluminescence imaging,transplanted stem cells,stem cell fate,regenerative medicine
更新于2025-09-09 09:28:46
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Ultra-Narrowband Metamaterial Absorbers for High Spectral Resolution Infrared Spectroscopy
摘要： Metamaterial perfect absorbers (MPAs) are artificial materials composed of an array of subwavelength structures that manipulate electromagnetic waves to achieve extraordinary light absorption properties. Driven by the advent of the Internet of Things, MPAs are employed in microelectromechanical systems for the development of efficient and miniaturized IR detectors, imagers, and spectrometers, thanks to their lithographically tunable peak absorption, spectral selectivity, and ultrathin thickness. MPAs characterized by high absorptance in narrow spectral bands are particularly desirable for the implementation of high-resolution IR spectroscopic sensors. Yet, no accurate analytical model is currently available to guide the design of an MPA with ultra-narrow absorption bandwidth, while meeting all the stringent requirements for spectroscopic sensors. Here, a circuit model capable of accurately predicting spectral responses of metal–insulator–metal (MIM) IR absorbers is reported. The model is experimentally validated in the mid-wavelength IR spectral range and exploited for the first demonstration of an MIM IR absorber that exhibits performance approaching the predicted physical limits: full-width at half-maximum ≈3% and near-unity absorption (η > 99.7%) at 5.83 μm wavelength, while independent of incident angle and polarization of the impinging IR radiation. These unprecedented absorption properties are key enablers for the development of miniaturized, low-cost, and high-resolution spectrometers.
关键词： spectroscopy,microelectromechanical system,plasmonics,infrared absorbers,metamaterials
更新于2025-09-09 09:28:46