Photoelectric Detection Research Articles

Ultrafast and hypersensitized detection based on van der Waals connection in two-dimensional WS2/Si structure

WS2, as a typical transition-metal dichalcogenides (TMDs) with strong light–matter interaction, exhibits great potential for highly-responsive photoelectric detectors. In this work, a series of WS2 nano-films with different thicknesses are successfully prepared on Si substrate by atomic layer deposition (ALD) and present a high-performance lateral photovoltaic effect (LPE). It shows high position sensitivity (up to 232 mV mm−1) and ultrafast response speed of 4.1 μs with little signal degeneration because of the strong light absorptivity and carrier mobility in the layered structure connected by van der Waals force. In addition, we find the absorption wavelength of lateral photovoltage (LPV) has changed significantly when WS2 thickness decreases to several layers. We attribute this phenomenon to the increasing indirect band-gap of WS2. It establishes an association between materials bandgap and LPV, which may suggest a potential approach for the characterization of theof bandgap and thickness of 2D materials.

Sensorless LED display screen interaction and object recognition

AbstractTaking advantage of the photoelectric characteristics of LED other than the light‐emitting function, this paper proposes a light sensing detection method and system without adding additional sensors to the LED screen. A two‐pole detection structure with a function of detecting positive and negative voltage is introduced to the LED drive circuit, which ensures the high‐speed characteristics during detection. What's more, the LED is controlled to work in photoconductive mode to obtain high voltage sensitivity when the intensity of incident light changes. The proposed module can reach an optical signal response rate of 19.1 μs with a detection rate of 23.5 Hz without affecting the original display function. The optical signal detection can reach a voltage sensitivity of 3.02 mV per lx. To verify the photoelectric detection capability of the method presented in this paper, a brand‐new screen object recognition system is built and tested. An 8 × 8 LED display module is used in experiment, and the scale of LED screen can be expanded easily and flexibly. In an ideal environment, a recognition accuracy of 99.25% can be achieved, while the recognition accuracy can still reach over 96.5% in a complex light environment. Therefore, this work has further application possibilities for light interaction and fast object recognition in large screens.

Ultra-broadband absorber based on cascaded nanodisk arrays

An ultra-broadband perfect absorber consisting of cascaded nanodisk arrays is demonstrated by placing insulator–metal–insulator–metal nanodisks on insulator–metal film stacks. The absorber shows over 90% absorption in a wavelength range between 600 nm and 4000 nm under transverse magnetic (TM) polarization, with an average absorptivity of 91.5% and a relative absorption bandwidth of 147.8%. The analysis of the electric field and magnetic field show that the synergy of localized surface plasmons, propagating surface plasmons, and plasmonic resonant cavity modes leads to the ultra-broadband perfect absorption, which accords well with the results of impedance-matched analysis. The influences of structural parameters and different metal materials on absorption performance are discussed. Furthermore, the absorber is polarization-independent, and the absorption remains more than 90% at a wide incident angle up to 40° under TE polarization and TM polarization. The designed ultra-broadband absorber has promising prospects in photoelectric detection and imaging.

Design of Photoelectric Inclination Sensor and Its Application in Target Tracking

As a sensor that converts angle signal into an electrical signal, the inclination sensor is applied in multiple fields. The photoelectric inclination sensor has the advantages of non-contact and high precision, but it is limited to small angle precision measurement and is expensive. A new photoelectric inclination sensor is obtained by combining photoelectric detection with elastic sensing elements and eliminating vibration or other interference errors based on an electromagnetic feedback system. The structure of the whole prototype is designed, the elastomer is calculated theoretically, the electromagnetic feedback part is designed and selected, the voltage-displacement characteristic test of the photodiode is carried out, and the linear interval is calibrated simultaneously. According to the voltage difference generated by the photodiode, a differential amplification circuit is designed to amplify the small voltage signal. The PID regulating circuit is designed to regulate the current on the electromagnetic coil. The A/D chip is used for analog-to-digital conversion, and the data are collected and uploaded through STM32 and RS485. In the test, the prototype test environment is built. It is proved that 0°∼45° is a linear range of the sensor in the open-loop system without electromagnetic feedback. The nonlinearity is 4.365%, the nonlinearity in the −20°~20° interval is less than 1.2%, and the 45°˜90° is the nonlinear range. In the closed-loop system of electromagnetic feedback, the interval of 0°˜90° is linear, the nonlinearity is 6.861%, and the nonlinearity of 0°˜45° is only 1.06%. This type of sensor is used for multi-station maneuvering target tracking. The aircraft to be tested is simulated and analyzed 100 times. It is found that adding a sensor monitoring station can improve the measurement accuracy and suppress the noise. In the closed-loop system of electromagnetic feedback, 0°˜90° is the linear range, the nonlinearity is 6.861%, and the nonlinearity of 0°˜45° is only 1.06%. Such sensor is used for multi-station maneuvering target tracking, and the aircraft to be tested is simulated and analyzed 100 times. Azimuth, pitch angle and errors from target to the sensor are calculated. The results show that the measurement accuracy can be improved and the noise can be suppressed by adding sensor monitoring stations.

Low-cost portable bioluminescence detector based on silicon photomultiplier for on-site colony detection

A low-cost, portable bioluminescence detector based on a silicon photomultiplier (SiPM) was developed for on-site colony detection, the main components of which are a low-noise photoelectric signal detection and processing circuit, power management module, and high-performance embedded microcontroller subsystem with peripheral circuits. Balanced chopper modulation and lock-in amplification techniques were adopted to improve the signal-to-noise ratio, and a zero-adjustment technique was used to eliminate the dark current of the SiPM to expand the dynamic range. Using this bioluminescence detector, adenosine triphosphate could be determined in the range of 3.6 × 10−6 to 3.6 × 10−11 mol/L, and bacterial colonies could be determined in the range of 1.0 × 103 to 1.0 × 109 CFU/mL, with a limit of quantitation of 1.0 × 103 CFU/mL. Satisfactory recoveries and precision were obtained. Actual samples were accurately tested and the data were verified by comparison with those from the national standard method. The manufacturing cost of the bioluminescence detector was only $30, which is only approximately 1% of the price of current commercial instruments. This study provides a tool for rapid on-site detection of bacterial colonies, as well as a new concept for the development of low-cost portable detection equipment.

A Probabilistic Calculation Method of Transformer Temperature Fault Based on Photoelectric Infrared Sensor

Aiming at the defect of the lack of quantitative detection probability evaluation method, we design two models which affect the detection probability of image fusion system. They are spectral contrast modeling of target and background and probability model of transformer fault detection and recognition under the influence of multiple factors. Based on the infrared optical imaging method, we established the fault identification model of multi-mode transformer or its connected parts; Studied several infrared optical imaging fusion test systems, and deduced the calculation method of transformer fault detection based on false alarm probability; Analyzed the correlation between the detection ability of the detection system and the characteristics of the target itself, environmental illumination, detection distance and so on. According to the relationship among SNR, detection range and detection probability, we derived the calculation model of target detection probability of optical imaging system under complex background. Through calculation and experimental analysis, the results show that the proposed method can effectively evaluate the detection probability of photoelectric detection imaging system under different background in practical application.

A comprehensive dual-spectroscopy detection technique based on TDLAS and QEPAS using a quartz tuning fork

A comprehensive dual-spectroscopy detection technique based on tunable diode laser absorption spectroscopy (TDLAS) and quartz enhanced photoacoustic spectroscopy (QEPAS) is demonstrated using a single quartz tuning fork (QTF) for signal detection. The QTF was utilized as an acoustic wave transducer for QEPAS signal detection. The QTF also served as a photoelectric detector for TDLAS signal detection based on the thermoelastic effect. The dual-spectroscopy detection structure was designed for TDLAS and QEPAS detection. The on-beam acoustic micro resonator (AMR) structure was placed on the upper end of the QTF for QEPAS signal enhancement, and the laser beam transmitted through the AMR was aligned to the QTF prong by an optical collimator for TDLAS signal detection. An absorption gas cell with an optical path length of 3 m was utilized in the TDLAS setup. The gas cell enhanced the absorption signal of the gas by virtue of its relatively long optical path. We tested the feasibility of the proposed dual-spectroscopy detection technique by detecting acetylene (C2H2) at 1532.83 nm. The experimental show that the signal of the dual-spectroscopy detection technique is approximately 1.13 times that of the QEPAS signal. The proposed dual-spectroscopy detection technique also showed superior gas sensing capability for trace gas detection and could achieve a minimum detection limit of 1.05 ppm. The signal strength of the proposed dual-spectroscopy detection technique can be further enhanced by using an absorption gas cell with a longer optical path.

A structure optimization for integrated binary reconfigurable true time delay lines

The structure optimization for a binary reconfigurable true time delay lines (RTTDL) based on the Mach–Zehnder interferometer (MZI) switches is proposed. Firstly, the number of the variable optical attenuator (VOA), which is generally used to make up for the imperfectness of the MZI switch and improves the RTTDL ’s flatness of broadband amplitude response and the delay accuracy, is minimized. Meanwhile, by adopting a pair of photoelectric detectors (PD) between every two MZI switches for power monitoring, the initialization time can be greatly reduced owing to the realization of the parallel initialization. On the other hand, with the help of the PDs, a continuously adjustable delay scheme is put forward by adjusting the allocation ratio of the last MZI switch. The proof-of-principle calculations are carried out to verify the optimization. The results show that the proposed optimization not only reduces the power consumption, the optical link loss and the integration volume caused by the VOAs, but also solves the problem that the binary RTTDL has only discrete delay states.

Research on the New Type of Error Detection Platform for Photoelectric Encoder

In order to realize the error detection of high precision optical encoder, an error detection method of optical encoder based on optical continuous closed loop (OCCL) was proposed, by the principle of small angle measurement of photoelectric autocollimator and single reflector. Firstly, the configuration of the OCCL error detection platform for optical encoder is designed. Then, the error detection principle of the OCCL optical encoder is analyzed. Finally, the OCCL photoelectric encoder error detection system is established, and the calibration auto-collimator and the regular 23-hedral polyhedron are used to calibrate the accuracy of the detection system. The experimental results show that the new photoelectric encoder error detection platform is frequent, convenient, stable and reliable, and the accuracy of the detection platform can reach 1.64” in the rated working speed range, which can meet the requirements of high precision (2”) and 360° full circle continuous error detection for the encoder.

Design of temperature monitoring system of 35 kV km-Level Domestic Second Generation High Temperature Superconducting Power Cable in Shanghai, China

The city of Shanghai, China plans to deploy the first domestic 35 kV km-level High-Temperature Superconducting Power Cable (HTS-PC) project for connecting two substations in the downtown region in 2021, of which the HTS-PC can transport the current with a maximum value of 2200 A. The HTS-PC needs to operate at a temperature level of the liquid nitrogen temperature zone to maintain the electrically superconducting state. The real-time temperature information of the HTS-PC is crucial for its safe operation. Therefore, this paper proposes a temperature monitoring system suitable for the 35 kV km-level domestic HTS-PC. The system is based on the optical fiber temperature measurement technology and mainly consists of the optical generation, photoelectric detection, fiber sensor, signal acquisition, signal processing, and other components. The conclusion of this paper can be consulted in the operation of the high-temperature superconducting power cable project in the future.

Кодирование изображений выборками отсчетов, мотивированное механизмами регистрации излучения в зрительной системе человека.

The paper presents the results of a study of input video data adequate formation/coding in modern imaging systems. Adequacy is understood here as the maximal correspondence between the ways of the radiation registration by material detectors and the ways of data coding in the retina of the human visual system. In this connection, the paper discusses general statistical issues of (photo) counts photoelectric detection and, on this basis, formalizes the concept of an ideal image formation by (ideal) visualization device. The problems arising in practice when working directly with ideal images are discussed and a method of their reduction to count sample of fixed (controllable) size, which, in fact, constitute the representation (coding) of registered data, is proposed. Results of illustrative computational experiments on count coding of the common digital images given by pixel data are presented. Examples of count samples of different sizes generated for the tested digital image are given. Based on the given results, the dependence of characteristics of sampling representations on the parameter of sample size is discussed.

Target Association and Management Engineering Application of Photoelectric Detection of Ground Mobile Platform

On the basis of the current detection methods and the target information obtained of ground mobile platform, this paper constructed the architecture of target management of mobile platform, put forward the target association and management solution based on image recognition, tracking, laser ranging, and situation sharing, initially completed the engineering realization through position association algorithm, and installed on a special unmanned vehicle by computer simulation, verified this software, the verification results show that this architecture can complete the functions of multi-source target management in mobile platform, it could access the mobile platform software architecture of existing models, could realize the target position association and had good engineering application value.

Indoor Ambient Temperature and Light Automatic Detection System

This paper designs an automatic detection system for indoor temperature and light temperature based on STC12C5A60S2 single-chip microcomputer. The whole system is composed of a host control module, a photoelectric detection module, an analog-to-digital conversion module, a temperature detection module, a voice broadcast module and a liquid crystal display module. The ambient temperature and light conditions are detected by the temperature sensor DS18B20 and the photoresistor, and the ISD1730 voice chip is used to realize the voice broadcast of the temperature value and the light condition. At the same time, the liquid crystal LCD 12864 is used to display the current temperature value and the illuminance value. The system has been tested to be stable, with low power consumption, small size and economical advantages.

Design and analysis of laser photoelectric detection sensor

AbstractIn order to solve the problem of unstable detection and low detection ability of traditional photoelectric detection target in complex environment, a design method of laser photoelectric detection sensor is proposed. Laser photoelectric detection sensor with active and passive laser detection screen is formed by adding line laser to the traditional photoelectric detection target. According to the characteristics of laser echo energy when the projectile passing through the laser detection screen, the calculation model of the laser echo power received by the photoelectric detector under the random intersection of projectile and target is established, and the signal‐to‐noise ratio calculation function of the system is derived. Through the comparative test, the results show that the detection ability of the laser photoelectric detection sensor is obviously better than that of the traditional photoelectric detection target, especially in the low illumination environment; moreover, the signal‐to‐noise ratio of the laser photoelectric detection sensor still follows the law of decreasing with the increase of detection distance, and it keeps the detection characteristics of photoelectric detection system. By increasing the laser emission power, the signal‐to‐noise ratio of the laser photoelectric detection sensor is improved to a certain extent, and the detection ability of the system is improved. The results verify that the design method and theoretical model of photoelectric detection sensor proposed in this paper are scientific and feasible.

Temporal and spatial domain detection model and method of infrared photoelectric detection target.

To improve the detection ability of photoelectric detection targets under low-illumination conditions, based on the traditional infrared photoelectric detection targets, in this paper, we propose a design method for an infrared detection screen by using a double high-power line laser interactive layout auxiliary mode, and we form an active infrared photoelectric detection target. We then establish the calculations of the laser beam's illumination and the emission power of the pulse laser as a projectile passes through the infrared detection screen. According to the relation of the thickness of the infrared detection screen, the time period over which the projectile passes through the infrared detection screen, and the projectile's spatial position, we use the grid division method to establish the temporal- and spatial-domain echo power model and the output signal voltage function of the active infrared photoelectric detection target. Through calculations and experimental analysis, it is found that the echo power is reduced as the detection distance is increased, and the intensity of the echo power is not linear with the thickness of the detection screen or the length of the projectile in the temporal and spatial domains. The detection performance of the proposed active infrared photoelectric detection target is better than the traditional infrared photoelectric detection target, and it can be improved to a certain extent by increasing the laser emission power appropriately.

Technology CAD (TCAD) Simulations of Mg2Si/Si Heterojunction Photodetector Based on the Thickness Effect.

Research on infrared detectors has been widely reported in the literature. For infrared detectors, PbS, InGaAs, PbSe, InSb, and HgxCd1-xTe materials are the most widely used and have been explored for photodetection applications. However, these are toxic and harmful substances which are not conducive to the sustainable development of infrared detectors and are not eco-friendly. Mg2Si is a green, healthy, and sustainable semiconductor material that has the potential to replace these toxic and damaging photoelectric materials, making photoelectric detectors (PDs) green, healthy, and sustainable. In this work, we report on the results of our simulation studies on the PN junction Mg2Si/Si heterojunction PD. A model structure of Mg2Si/Si heterojunction PD has been built. The effects of Mg2Si and Si layer thickness on the optical and electrical performance of Mg2Si/Si heterojunction PD are discussed. For the purpose of this analysis, we consider electrical performance parameters such as I–V curve, external quantum efficiency (EQE), responsivity, noise equivalent power (NEP), detectivity, on-off ratio, response time, and recovery time. The simulation results show that the Mg2Si/Si heterojunction PD shows optimum performance when the thickness of Si and Mg2Si layers are 300 nm and 280 nm, respectively. For the optimized structure, the reverse breakdown voltage was found to be −23.61 V, the forward conduction voltage was 0.51 V, the dark current was 5.58 × 10−13 A, and the EQE was 88.98%. The responsivity was found to be 0.437 A/W, the NEP was 6.38 × 10−12 WHz1/2, and the detectivity was 1.567 × 1011 Jones. With the on-off ratio of 1566, the response time was found to be 0.76 ns and the recovery time was 5.75 ns. The EQE and responsivity peak wavelength of PD show a redshift as the thickness of Mg2Si increases. The Mg2Si heterojunction PD can effectively detect infrared light in the wavelength range of 400 to 1400 nm. The simulation results can be utilized to drive the development of green Mg2Si/Si heterojunction PD in the future.

Performance analysis of photo-electrochemical photodetector based on liquid-phase exfoliation few-layered graphdiyne nanosheets

Abstract The band gap of two-dimensional (2D) materials become a hot issue for photoelectric detection. Recently, public attention is thoroughly aroused as to the remarkable electrical transport characteristic and super photoresponse of 2D graphdiyne. The simulation results show that the photoresponse can be adjusted in various solutions based on the graphdiyne nanosheets with different sizes and thicknesses. Based on few-layered graphdiyne nanosheets prepared by a liquid-phase exfoliation method, a photoelectrochemical (PEC)-type few-layered graphdiyne photodetector is demonstrated in this paper. A group of PEC tests are carried out in neutral solution to verify the simulation results. The as-prepared graphdiyne photodetector possesses high photocurrent density, effective responsivity and excellent cycle stability in condition of KCl electrolyte and solar illuminance. The detectivity of the PEC-type graphdiyne photodetector can be easy to adjust by altering electrolyte concentration and other corresponding parameters, which indicates the proposed equipment can be a good candidate for photoelectric detection.

Real-time in situ detection and source tracing of different soot

Coal combustion produces large amounts of carbon dioxide, sulfur dioxide and metal ions. They are the main causes of greenhouse effect, acid rain and haze-fog respectively. It brings a great threat to the environment and human health. As a new photoelectric detection technology, laser-induced breakdown spectroscopy (LIBS) has become an important method in the field of environmental monitoring. In this paper, LIBS is applied to real-time in situ detection of soot from burning different coal. It is found that the main elements in soot are Al, Fe, Ca, Mg, Mn, Si, Sr and Na. In addition, the CN molecular bands can be observed. By comparing the spectra of different samples, differences between them are discussed. What’s more, principal component analysis (PCA) is used for data dimensionality reduction. After that, the data is distributed in a three-dimensional space, and then different kinds of soot are classified successfully. Combined with error back propagation training artificial neural networks (BP-ANN), the source tracing of soot from different coal are conducted, and the results are very good. The recognition accuracy is more than 92%. It is proved that this method is very promising for the detection and identification of soot. It is of great benefit to the environment and human health.

Three-dimensional coordinates test method with uncertain projectile proximity explosion position based on dynamic seven photoelectric detection screen

To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is established. According to the relation of the dynamic seven photoelectric detection screen planes and the time values, the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.

Selectively enhanced violet and infrared position sensitive photodetectors based on RTA treated ZnO/Si

Position sensitive detectors (PSDs) based on lateral photovoltaic effect (LPE) are extremely versatile in many areas. Generally speaking, it has an optimal operating frequency which corresponding to the best sensitivity. How to effectively adjust a certain operating frequency in a fixed structure and achieve a large sensitivity improvement has always been a challenge. Here, we demonstrate an unusual selectively enhanced violet and near-infrared LPE observed in rapid thermal annealing (RTA) treated ZnO/Si homo-heterostructure. It exhibits excellent performance in the wavelength of 445 nm and 980 nm, and the optimum lateral photovoltage (LPV) sensitivity can be controlled by manipulating the annealing temperature. Notably, the optical response time of the annealed sample is increased by about 25 times compared with the as-deposited one. We attribute this anomalous effect to the defect ionization in ZnO layer, as well as the resistivity change after annealing. This work suggests an effective approach that can selectively enhance the sensitivity of PSDs in violet and infrared region. Moreover, it shows high sensitivity and fast photoresponse speed, which may open new paths toward violet and infrared photoelectric detection.