A novel light scattering technique for mapping metal surface corrosion is presented and its results on copper exposed to atmosphere are reported. The front end of the instrument is made up of a sensor module comprisin...A novel light scattering technique for mapping metal surface corrosion is presented and its results on copper exposed to atmosphere are reported. The front end of the instrument is made up of a sensor module comprising a thin beam light emitting diode (LED) illuminating a small spot on the metal surface, and a matched pair of photodetectors, one for capturing the reflected light and the other for sampling the scattered light. The analog photocurrent signals are digitized and processed online by a personal computer (PC) to determine the corrosion factor defined in terms of the two current values. By scanning the sample surface using the light beam and by computing the corrosion factor values simultaneously, a three dimensional graph and a two dimensional contour map are generated in the PC using Matlab tools. The values of the corrosion factor measured in different durations of exposure to atmosphere, which obey a bilogarithmic law, testify to the validity of our mathematical model.展开更多
High-performance interrogation systems for optical fiber sensors are extensively required for environmental condition monitoring applications.In this article,we propose and demonstrate a Michelson interferometer(MI)in...High-performance interrogation systems for optical fiber sensors are extensively required for environmental condition monitoring applications.In this article,we propose and demonstrate a Michelson interferometer(MI)interrogation system based on an optoelectronic oscillator(OEO).The frequency of the OEO is related to the free spectral range(FSR)of the MI.Thus,when the FSR of the MI varies with a change in external physical factors,the frequency of the OEO shifts and can be used for interrogation.We demonstrate that the temperature sensitivity and interrogation resolution are 35.35 MHz/℃and 0.012℃,respectively.Such an OEO-based scheme enables wavelength-to-frequency mapping and promises a wide linear interrogation range,high resolution and high-speed interrogation.展开更多
Gas sensor is an indispensable part of modern society withwide applications in environmental monitoring,healthcare,food industry,public safety,etc.With the development of sensor technology,wireless communication,smart...Gas sensor is an indispensable part of modern society withwide applications in environmental monitoring,healthcare,food industry,public safety,etc.With the development of sensor technology,wireless communication,smart monitoring terminal,cloud storage/computing technology,and artificial intelligence,smart gas sensors represent the future of gassensing due to their merits of real-time multifunctional monitoring,earlywarning function,and intelligent and automated feature.Various electronicand optoelectronic gas sensors have been developed for high-performancesmart gas analysis.With the development of smart terminals and the maturityof integrated technology,flexible and wearable gas sensors play an increasingrole in gas analysis.This review highlights recent advances of smart gassensors in diverse applications.The structural components and fundamentalprinciples of electronic and optoelectronic gas sensors are described,andflexible and wearable gas sensor devices are highlighted.Moreover,sensorarray with artificial intelligence algorithms and smart gas sensors in“Internet of Things”paradigm are introduced.Finally,the challengesand perspectives of smart gas sensors are discussed regarding the future need of gas sensors for smart city and healthy living.展开更多
Nanocrystalline copper oxide (CuO) thin films were deposited onto glass substrates by a spin coating technique using an aqueous solution of copper acetate. These films were characterized for their structural, mor-phol...Nanocrystalline copper oxide (CuO) thin films were deposited onto glass substrates by a spin coating technique using an aqueous solution of copper acetate. These films were characterized for their structural, mor-phological, optoelectronic properties by means of X-ray diffraction (XRD) scanning electron microscopy (SEM), UVspectroscopy and four probe method. The CuO films are oriented along (1 1 1) plane with the monoclinic crystal structure. These films were utilized in H2S sensors. The dependence of the H2S response on the operating temperature, H2S concentration of CuO film (annealed at 700。C) was investigated. The CuO film showed selectivity for H2S. The maximum H2S response of 25.2 % for the CuO film at gas concentra-tion of 100 ppm at operating temperature 200oC was achieved.展开更多
The rapid development of internet of things(loT)urgently needs edge miniaturized computing devices with high efficiency and low-power consumption.In-sensor computing has emerged as a promising technology to enable in-...The rapid development of internet of things(loT)urgently needs edge miniaturized computing devices with high efficiency and low-power consumption.In-sensor computing has emerged as a promising technology to enable in-situ data processing within the sensor array.Here,we report an optoelectronic array for in-sensor computing by integrating photodiodes(PDs)with resistive random-access memories(RRAMs).The PD-RRAM unit cell exhibits reconfigurable optoelectronic output and photo-responsivity by programming RRAMs into different resistance states.Furthermore,a 3×3 PD-RRAM array is fabricated to demonstrate optical image recognition,achieving a universal architecture with ultralow latency and low power consumption.This study highlights the great potential of the PD-RRAM optoelectronic array as an energy-effcient in-sensor computing primitive for future IoT applications.展开更多
The latest developments in bio-inspired neuromorphic vision sensors can be summarized in 3 keywords:smaller,faster,and smarter.(1)Smaller:Devices are becoming more compact by integrating previously separated component...The latest developments in bio-inspired neuromorphic vision sensors can be summarized in 3 keywords:smaller,faster,and smarter.(1)Smaller:Devices are becoming more compact by integrating previously separated components such as sensors,memory,and processing units.As a prime example,the transition from traditional sensory vision computing to in-sensor vision computing has shown clear benefits,such as simpler circuitry,lower power consumption,and less data redundancy.(2)Swifter:Owing to the nature of physics,smaller and more integrated devices can detect,process,and react to input more quickly.In addition,the methods for sensing and processing optical information using various materials(such as oxide semiconductors)are evolving.(3)Smarter:Owing to these two main research directions,we can expect advanced applications such as adaptive vision sensors,collision sensors,and nociceptive sensors.This review mainly focuses on the recent progress,working mechanisms,image pre-processing techniques,and advanced features of two types of neuromorphic vision sensors based on near-sensor and in-sensor vision computing methodologies.展开更多
The principle of fiber optics coupling pressure sensor with micro-power dissipation is introduced as well as the use of two-way signal single fiber transfer(measure signal and reference signal)to conduct a proportiona...The principle of fiber optics coupling pressure sensor with micro-power dissipation is introduced as well as the use of two-way signal single fiber transfer(measure signal and reference signal)to conduct a proportional measure.It also discusses the adopted ways for improving the stability temperature drift and the noise of the measuring system.展开更多
1 Results One dimensional (1D) nanostructures such as nanowires,nanotubes,nanorods and nanoribbons have been extensively investigated for a wide range of applications[1].Here,we present the synthesis,characterization ...1 Results One dimensional (1D) nanostructures such as nanowires,nanotubes,nanorods and nanoribbons have been extensively investigated for a wide range of applications[1].Here,we present the synthesis,characterization and technological applications of several 1D nanostructures including SnO2 nanowires,CuO nanoribbons,CdSe nanowires and In2O3 nanowires.SnO2 nanowires were synthesized by thermal evaporation combined with a self-catalyzed growth procedure.Scanning electron microscopy (SEM) observation shows...展开更多
Optoelectronic devices,including light sensors and light-emitting diodes,are indispensable for our daily lives.Lead-based optoelectronic materials,including colloidal quantum dots and lead-halide perovskites,have emer...Optoelectronic devices,including light sensors and light-emitting diodes,are indispensable for our daily lives.Lead-based optoelectronic materials,including colloidal quantum dots and lead-halide perovskites,have emerged as promising candidates for the next-generation optoelectronic devices.This is primarily attributed to their tailorable optoelectronic properties,industrialization-compatible manufacturing techniques,seamless integration with silicon technology and excellent device performance.In this perspective,we review recent advancements in lead-based optoelectronic devices,specifically focusing on photodetectors and active displays.By discussing the current challenges and limitations of lead-based optoelectronics,we find the exciting potential of on-chip,in-situ fabrication methods for realizing high-performance optoelectronic systems.展开更多
Neuromorphic systems represent a promising avenue for the development of the next generation of artificial intelligence hardware.Machine vision,one of the cores in artificial intelligence,requires system-level support...Neuromorphic systems represent a promising avenue for the development of the next generation of artificial intelligence hardware.Machine vision,one of the cores in artificial intelligence,requires system-level support with low power consumption,low latency,and parallel computing.Neuromorphic vision sensors provide an efficient solution for machine vision by simulating the structure and function of the biological retina.Optoelectronic synapses,which use light as the main means to achieve the dual functions of photosensitivity and synapse,are the basic units of the neuromorphic vision sensor.Therefore,it is necessary to develop various optoelectronic synaptic devices to expand the application scenarios of neuromorphic vision systems.This review compares the structure and function for both biological and artificial retina systems,and introduces various optoelectronic synaptic devices based on low-dimensional materials and working mechanisms.In addition,advanced applications of optoelectronic synapses as neuromorphic vision sensors are comprehensively summarized.Finally,the challenges and prospects in this field are briefly discussed.展开更多
根据CO分子在中红外波段的吸收特性,利用红外热辐射光源(IR55)和双通道热释电探测器(LM244),研制了一种差分式CO检测仪。通过双通道锁相放大器对探测器输出的两路信号进行处理,有效地抑制了系统噪声,提高了仪器的检测精度。介绍了系统...根据CO分子在中红外波段的吸收特性,利用红外热辐射光源(IR55)和双通道热释电探测器(LM244),研制了一种差分式CO检测仪。通过双通道锁相放大器对探测器输出的两路信号进行处理,有效地抑制了系统噪声,提高了仪器的检测精度。介绍了系统的检测原理,给出了光学系统和双通道锁相放大器的实现方案,该锁相放大器能提取的最小标准信号幅度为1 m V,移相误差小于0.2%。利用配备的体积分数为0~1×10^(-3)的CO样品,开展了气体检测实验。实验结果表明:系统的检测下限为1×10^(-5),相对测量误差小于15%。当气体体积分数为0×10^(-6)时,测得浓度的波动范围为-5.2×10^(-6)~6.2×10^(-6)。考虑静态配气时气体在气室中扩散的时间,仪器的响应时间约为58~62 s。同基于量子级联激光器和分布反馈激光器的CO检测仪相比,所研制的仪器具有结构简单、性价比高等优势,在煤矿、环保等场合的CO检测方面具有较好的应用前景。展开更多
文摘A novel light scattering technique for mapping metal surface corrosion is presented and its results on copper exposed to atmosphere are reported. The front end of the instrument is made up of a sensor module comprising a thin beam light emitting diode (LED) illuminating a small spot on the metal surface, and a matched pair of photodetectors, one for capturing the reflected light and the other for sampling the scattered light. The analog photocurrent signals are digitized and processed online by a personal computer (PC) to determine the corrosion factor defined in terms of the two current values. By scanning the sample surface using the light beam and by computing the corrosion factor values simultaneously, a three dimensional graph and a two dimensional contour map are generated in the PC using Matlab tools. The values of the corrosion factor measured in different durations of exposure to atmosphere, which obey a bilogarithmic law, testify to the validity of our mathematical model.
文摘High-performance interrogation systems for optical fiber sensors are extensively required for environmental condition monitoring applications.In this article,we propose and demonstrate a Michelson interferometer(MI)interrogation system based on an optoelectronic oscillator(OEO).The frequency of the OEO is related to the free spectral range(FSR)of the MI.Thus,when the FSR of the MI varies with a change in external physical factors,the frequency of the OEO shifts and can be used for interrogation.We demonstrate that the temperature sensitivity and interrogation resolution are 35.35 MHz/℃and 0.012℃,respectively.Such an OEO-based scheme enables wavelength-to-frequency mapping and promises a wide linear interrogation range,high resolution and high-speed interrogation.
基金supported by the National Natural Science Foundation of China(No.22376159)the Fundamental Research Funds for the Central Universities.
文摘Gas sensor is an indispensable part of modern society withwide applications in environmental monitoring,healthcare,food industry,public safety,etc.With the development of sensor technology,wireless communication,smart monitoring terminal,cloud storage/computing technology,and artificial intelligence,smart gas sensors represent the future of gassensing due to their merits of real-time multifunctional monitoring,earlywarning function,and intelligent and automated feature.Various electronicand optoelectronic gas sensors have been developed for high-performancesmart gas analysis.With the development of smart terminals and the maturityof integrated technology,flexible and wearable gas sensors play an increasingrole in gas analysis.This review highlights recent advances of smart gassensors in diverse applications.The structural components and fundamentalprinciples of electronic and optoelectronic gas sensors are described,andflexible and wearable gas sensor devices are highlighted.Moreover,sensorarray with artificial intelligence algorithms and smart gas sensors in“Internet of Things”paradigm are introduced.Finally,the challengesand perspectives of smart gas sensors are discussed regarding the future need of gas sensors for smart city and healthy living.
文摘Nanocrystalline copper oxide (CuO) thin films were deposited onto glass substrates by a spin coating technique using an aqueous solution of copper acetate. These films were characterized for their structural, mor-phological, optoelectronic properties by means of X-ray diffraction (XRD) scanning electron microscopy (SEM), UVspectroscopy and four probe method. The CuO films are oriented along (1 1 1) plane with the monoclinic crystal structure. These films were utilized in H2S sensors. The dependence of the H2S response on the operating temperature, H2S concentration of CuO film (annealed at 700。C) was investigated. The CuO film showed selectivity for H2S. The maximum H2S response of 25.2 % for the CuO film at gas concentra-tion of 100 ppm at operating temperature 200oC was achieved.
基金the National Key Research and Development Program(2021YFA0716400)the National Natural Science Foundation of China(62225405,62350002,61991443,62127814,62235005,and 61927811)the Collaborative Innovation Center of Solid-State Lighting and Energy-Saving Electronics。
文摘The rapid development of internet of things(loT)urgently needs edge miniaturized computing devices with high efficiency and low-power consumption.In-sensor computing has emerged as a promising technology to enable in-situ data processing within the sensor array.Here,we report an optoelectronic array for in-sensor computing by integrating photodiodes(PDs)with resistive random-access memories(RRAMs).The PD-RRAM unit cell exhibits reconfigurable optoelectronic output and photo-responsivity by programming RRAMs into different resistance states.Furthermore,a 3×3 PD-RRAM array is fabricated to demonstrate optical image recognition,achieving a universal architecture with ultralow latency and low power consumption.This study highlights the great potential of the PD-RRAM optoelectronic array as an energy-effcient in-sensor computing primitive for future IoT applications.
基金This work was supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.NRF-2019R1A2C2002447)This research also was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.NRF-2014R1A6A1030419)This work also was supported by Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(P0020967,Advanced Training Program for Smart Sensor Engineers).
文摘The latest developments in bio-inspired neuromorphic vision sensors can be summarized in 3 keywords:smaller,faster,and smarter.(1)Smaller:Devices are becoming more compact by integrating previously separated components such as sensors,memory,and processing units.As a prime example,the transition from traditional sensory vision computing to in-sensor vision computing has shown clear benefits,such as simpler circuitry,lower power consumption,and less data redundancy.(2)Swifter:Owing to the nature of physics,smaller and more integrated devices can detect,process,and react to input more quickly.In addition,the methods for sensing and processing optical information using various materials(such as oxide semiconductors)are evolving.(3)Smarter:Owing to these two main research directions,we can expect advanced applications such as adaptive vision sensors,collision sensors,and nociceptive sensors.This review mainly focuses on the recent progress,working mechanisms,image pre-processing techniques,and advanced features of two types of neuromorphic vision sensors based on near-sensor and in-sensor vision computing methodologies.
文摘The principle of fiber optics coupling pressure sensor with micro-power dissipation is introduced as well as the use of two-way signal single fiber transfer(measure signal and reference signal)to conduct a proportional measure.It also discusses the adopted ways for improving the stability temperature drift and the noise of the measuring system.
文摘1 Results One dimensional (1D) nanostructures such as nanowires,nanotubes,nanorods and nanoribbons have been extensively investigated for a wide range of applications[1].Here,we present the synthesis,characterization and technological applications of several 1D nanostructures including SnO2 nanowires,CuO nanoribbons,CdSe nanowires and In2O3 nanowires.SnO2 nanowires were synthesized by thermal evaporation combined with a self-catalyzed growth procedure.Scanning electron microscopy (SEM) observation shows...
基金supported by the National Key Research and Development Program of China(Nos.2024YFA1209503 and 2021YFB3501800)the National Natural Science Foundation of China(Grant Nos.62322505 and 62374069)the Innovation Project of Optics Valley Laboratory(No.OVL2023ZD002).
文摘Optoelectronic devices,including light sensors and light-emitting diodes,are indispensable for our daily lives.Lead-based optoelectronic materials,including colloidal quantum dots and lead-halide perovskites,have emerged as promising candidates for the next-generation optoelectronic devices.This is primarily attributed to their tailorable optoelectronic properties,industrialization-compatible manufacturing techniques,seamless integration with silicon technology and excellent device performance.In this perspective,we review recent advancements in lead-based optoelectronic devices,specifically focusing on photodetectors and active displays.By discussing the current challenges and limitations of lead-based optoelectronics,we find the exciting potential of on-chip,in-situ fabrication methods for realizing high-performance optoelectronic systems.
基金National Key R&D program of China(Grant No.2019YFB1309701)National Natural Science Foundation of China(NSFC,Grand Nos.U1813211,61804009)Beijing Institute of Technology Research Fund Program for Young Scholars and Analysis&Testing Center,Beijing Institute of Technology.
文摘Neuromorphic systems represent a promising avenue for the development of the next generation of artificial intelligence hardware.Machine vision,one of the cores in artificial intelligence,requires system-level support with low power consumption,low latency,and parallel computing.Neuromorphic vision sensors provide an efficient solution for machine vision by simulating the structure and function of the biological retina.Optoelectronic synapses,which use light as the main means to achieve the dual functions of photosensitivity and synapse,are the basic units of the neuromorphic vision sensor.Therefore,it is necessary to develop various optoelectronic synaptic devices to expand the application scenarios of neuromorphic vision systems.This review compares the structure and function for both biological and artificial retina systems,and introduces various optoelectronic synaptic devices based on low-dimensional materials and working mechanisms.In addition,advanced applications of optoelectronic synapses as neuromorphic vision sensors are comprehensively summarized.Finally,the challenges and prospects in this field are briefly discussed.
文摘根据CO分子在中红外波段的吸收特性,利用红外热辐射光源(IR55)和双通道热释电探测器(LM244),研制了一种差分式CO检测仪。通过双通道锁相放大器对探测器输出的两路信号进行处理,有效地抑制了系统噪声,提高了仪器的检测精度。介绍了系统的检测原理,给出了光学系统和双通道锁相放大器的实现方案,该锁相放大器能提取的最小标准信号幅度为1 m V,移相误差小于0.2%。利用配备的体积分数为0~1×10^(-3)的CO样品,开展了气体检测实验。实验结果表明:系统的检测下限为1×10^(-5),相对测量误差小于15%。当气体体积分数为0×10^(-6)时,测得浓度的波动范围为-5.2×10^(-6)~6.2×10^(-6)。考虑静态配气时气体在气室中扩散的时间,仪器的响应时间约为58~62 s。同基于量子级联激光器和分布反馈激光器的CO检测仪相比,所研制的仪器具有结构简单、性价比高等优势,在煤矿、环保等场合的CO检测方面具有较好的应用前景。
