- 标题
- 摘要
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- 实验方案
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SPR based fiber optic sensor using IMO thin film: towards wide wavelength tunability from visible to NIR
摘要： Due to existence of free electrons, conducting metal oxides (CMOs) such as indium molybdenum oxide, can support surface plasmon resonance (SPR) at the interface of CMO and the dielectric. This research provides first theoretically implementation of Indium molybdenum oxide (IMO) as plasmonic layer in SPR fiber optic sensor. We demonstrate how changing the oxygen contents during IMO layer deposition could tune the operational wavelength of sensing probe in a wide range from visible to NIR which has a great significance in many biological and chemical environmental applications. Moreover, sensitivity and figure of merit of the proposed sensor have been calculated and compared for IMO thin films prepared at different oxygen contents.
关键词： Surface plasmon resonance,Indium molybdenum oxide,Optical fiber sensors,Wide wavelength tunability,Figure of merit,Sensitivity
更新于2025-09-04 15:30:14
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Quarter Video Graphics Array Digital Pixel Image Sensing With a Linear and Wide-Dynamic-Range Response by Using Pixel-Wise 3-D Integration
摘要： We have developed a quarter video graphics array (QVGA) digital pixel image sensor by using the 3-D integration technology. The pulse-frequency modulation (PFM) analog-to-digital converter (ADC) operates as a digital pixel, which overcomes the signal saturation due to the full well capacity of the photodiode (PD). We have also newly designed a PFM-ADC for pixels with a pinned PD and a floating diffusion to comply with the CMOS image sensor process used to attain high sensitivity and low noise. PDs, comparators, logic circuits, and counters are integrated into two silicon-on-insulator layers by pixel-wise 3-D integration with gold electrodes with a 5 μm diameter, thereby achieving a QVGA resolution for a 20-mm square chip in the 0.18- and 0.2-μm process nodes. The developed sensor exhibits both the excellent linearity and a wide-dynamic range of more than 96 dB. Video images with a high bit depth of 16 bit are also obtained to demonstrate the superior image sensing, capable of capturing the real world at high fidelity.
关键词： analog-to-digital converters (ADCs),dynamic range,image sensors,3-D integrated circuits,integrated circuit interconnections,pulse generation,silicon on insulator (SOI)
更新于2025-09-04 15:30:14
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Iterative Reweighted Tikhonov-regularized Multihypothesis Prediction Scheme for Distributed Compressive Video Sensing
摘要： Distributed compressive video sensing (DCVS) has great potential for signal acquisition and processing in source-limited communication, e.g., wireless video sensors network (WVSN), because it shifts complicated motion estimation and motion compensation from the encoder to the decoder. Known as a state-of-the-art technique in DCVS, multihypothesis (MH) prediction is widely used because of its acceptable performance and low computational complexity. However, this technique is restricted by inaccurate regularizations, which can cause susceptibility to inaccurate hypotheses. In this paper, we present an iterative reweighted Tikhonov-regularized scheme for MH prediction reconstruction. Specifically, to enhance robustness, this scheme proposes a reweighted Tikhonov regularization (MH-RTIK) that synthetically considers three factors that affect MH prediction performance—accuracy of the hypothesis set, number of hypotheses, and accuracy of regularizations—by utilizing the influence of each hypothesis. Furthermore, to avoid over-iteration in iterative MH prediction reconstruction, we propose a Bhattacharyya coefficient-based stopping criterion for use in the recovery of non-key frames, in which we exploit the similarity to an adjacent key frame rather than a previous iteration result. The simulation results show that the proposed scheme outperforms the state-of-the-art MH methods in terms of robustness to inaccurate hypotheses when there are a limited number of hypotheses.
关键词： Distributed compressive video sensing (DCVS),video reconstruction,wireless video sensors network (WVSN),multihypothesis (MH) prediction
更新于2025-09-04 15:30:14
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[ASME ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering - Madrid, Spain (Sunday 17 June 2018)] Volume 11B: Honoring Symposium for Professor Carlos Guedes Soares on Marine Technology and Ocean Engineering - Investigation on Temperature Compensation of Fiber Bragg Grating Sensors for Hull Monitoring
摘要： Hull monitoring system with Fiber Bragg Grating (FBG) sensors increasingly receives people's attentions. However, for the ship hull monitoring, the deformation of hull girder changes a lot as is subjected to a huge temperature variation. Therefore, the compensation method with only FBG temperature self-correction is not suitable for the hull monitoring sensors because no material thermal expansion effects are reasonably included. In this paper, the new compensation method of hull monitoring FBG sensor based on the sensor theory with both FBG temperature self-correction and steel thermal expansion effects correction is studied. The coupled compensation method suitable for hull monitoring sensor is obtained by theoretical derivation. As the comparison, the coupled compensation experiment was carried out. The results show that the relative error under the temperature compensation method is large in the case of drastic strain and temperature changes, and the correction results of the tested method will be closer to the true level.
关键词： temperature compensation,coupled compensation method,steel thermal expansion,hull monitoring,Fiber Bragg Grating (FBG) sensors
更新于2025-09-04 15:30:14
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Atomically Thin 2D‐Arsenene by Liquid‐Phased Exfoliation: Toward Selective Vapor Sensing
摘要： Phosphorene and antimonene, single- or few-layered (FL) semiconductor materials, have recently attracted enormous attention due to their unique properties, provided by their extreme thinness. Here, a liquid-phase exfoliation (LPE) procedure to prepare FL arsenene, another member of pnictogens, assisted by sonication and without any additional surfactant is reported. The exfoliation process is performed in various solvents. Among those, N-methylpyrrolidone is found to provide the highest concentration of stable arsenene sheets. Spectroscopic and microscopic analyses confirm the formation of high-quality few-layer arsenene nanosheets with large lateral dimensions. An application of this material for construction of vapor sensor based on electrochemical impedance spectroscopy is demonstrated. The device detects selectively methanol or acetone vapors depending on the selected resonance frequency. The results are highly reproducible, and the vapor sensor has long-term stability.
关键词： centrifugation,arsenic,2D arsenene,vapor sensors,liquid-phase exfoliation
更新于2025-09-04 15:30:14
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The Cryogenic AntiCoincidence Detector for ATHENA X-IFU: Assessing the Role of the Athermal Phonons Collectors in the AC-S8 Prototype
摘要： The ATHENA X-ray observatory is the second large-class mission in the ESA Cosmic Vision 2015–2025 science programme. One of the two on-board instruments is the X-IFU, an imaging spectrometer based on a large array of TES microcalorimeters. To reduce the particle-induced background, the spectrometer works in combination with a cryogenic anticoincidence detector (CryoAC), placed less than 1 mm below the TES array. The last CryoAC single-pixel prototypes, namely AC-S7 and AC-S8, are based on large-area (1 cm2) silicon absorbers sensed by 65 parallel-connected iridium TES. This design has been adopted to improve the response generated by the athermal phonons, which will be used as fast anticoincidence ?ag. The latter sample is featured also with a network of aluminum ?ngers directly connected to the TES, designed to further improve the athermals collection ef?ciency. In this paper, we will report the main results obtained with AC-S8, showing that the additional ?ngers network is able to increase the energy collected from the athermal part of the pulses (from the 6% of AC-S7 up to the 26 % with AC-S8). Furthermore, the ?nger design is able to prevent the quasiparticle recombination in the aluminum, assuring a fast pulse rising front (L/R limited). In our road map, the AC-S8 prototype is the last step before the development of the CryoAC demonstration model, which will be the detector able to demonstrate the critical technologies expected in the CryoAC development programme.
关键词： Transition edge sensors,Anticoincidence,ATHENA,X-rays: detectors
更新于2025-09-04 15:30:14
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Tunable Fano resonances in a robust quasicylindrical microresonator photonic system
摘要： The control of Fano resonances is of critical importance to opto-electronic and all-optical switching devices, light delay and storage, high sensitivity sensors, and quantum information processors. In this paper, we controllable electromagnetically induced transparency (EIT)-like and Fano resonances can be achieved in a single quasi-cylindrical microresonator (QCMR). Robust and selective excitation of localized axial modes in a high quality QCMR is firstly demonstrated. Based on this stable platform, EIT-like lineshapes can be tuned and converted into Fano resonances by vertically moving the resonator. Moreover, by horizontally scanning the resonator, the transmission spectrum exhibits periodically changed Fano-like lineshapes. It is reported for the first time that the above two kinds of Fano resonances originated from different mechanisms can work on the same mode simultaneously. Our approach, demonstrated in this work, provides a robust photonic platform for accessing, controlling, and engineering the Fano resonances.
关键词： high sensitivity sensors,opto-electronic devices,electromagnetically induced transparency,Fano resonances,quasi-cylindrical microresonator
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Saint Petersburg, Russia (2018.10.22-2018.10.23)] 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Study of Gas-Sensitive Properties of Zinc Oxide Nanorod Array at Room Temperature
摘要： In this paper, we present a technique for the synthesis of zinc oxide nanorods and the study of their sensitivity to organic solvent vapors. Zinc oxide nanorods were synthesized by hydrothermal method. Investigation of gas-sensitive properties was carried out by the method of impedance spectroscopy. Studies of gas-sensitive properties of zinc oxide showed a significant response of the system to the vapor of reducing gases at room temperature. It is shown that the thickness of the seed layer and, correspondingly, the density of the structure on the basis of ZnO nanorods, strongly affect the sensitivity of the sensor.
关键词： impedance spectroscopy,nanorods,hydrothermal synthesis,zinc oxide,gas sensors
更新于2025-09-04 15:30:14
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Synthesis and Photophysical Characterization of Proton Transfer-Based Thiourea Derivatives: Potential Application as Colorimetric Naked-Eye Chemosensor for Fluoride Detection in Solution
摘要： Two new thiourea derivatives were synthesized through the reaction of photoactive aminohydroxybenzazoles and p-isothiocyanate benzoic acid via nucleophilic addition reaction. The compounds were characterized using high resolution mass spectrometry with eletrospray ionization (HRMS-ESI), Fourier transform infrared (FTIR), 13C and 1H nuclear magnetic resonance (NMR) spectroscopies. UV-Vis and steady-state fluorescence in solution were also applied to characterize their photophysical behavior. The compounds present absorption in the ultraviolet region (ca. 300 nm) and fluorescence emission with a large Stokes’ shift in the UV-A and green region, with the longer wavelength related to phototautomerism in the excited state (ESIPT). Both compounds were investigated as optical sensors for the detection of anions in solution, presenting a potential application for fluoride ion detection by naked-eye and UV-Vis spectroscopy. The continuous variation method plot gave a 1:1 stoichiometric ratio between the chemosensors and F– for the new formed species. The UV-Vis and 1H NMR titration experiments reflect the establishment of a hydrogen bond interaction between the thiourea moiety of the chemosensors and fluoride. In addition, the presence of fluoride in solution tailored the fluorescence emission of one compound favoring the ESIPT emission.
关键词： fluorescence,optical sensors,fluoride ion,ESIPT,benzazoles
更新于2025-09-04 15:30:14
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Desenvolvimento de filmes poliméricos ultrafinos e reticulados para aplica??es em sensores
摘要： A new method for producing stable films used in sensors is proposed, based on the layer-by-layer deposition of poly(o-ethoxyaniline) and phenol-formaldehyde (POEA/PF) followed by a thermal treatment to promote film crosslinking. The crosslinking process was characterized by Fourier transform infrared and ultraviolet-visible spectroscopic analyses, atomic force microscopy and desorption studies. Sensor analyses were also carried out in order to evaluate cross-linked sensor signal. Results showed that PF resin served as a curing agent, forming a semi-interpenetrating polymer network therefore producing stable films. Although there was a decrease in the sensitivity of sensors with crosslinking, such films are quite stable and can be potentially used in sensors, especially where higher stability is required.
关键词： ultrathin films,conductive polymers,sensors
更新于2025-09-04 15:30:14