Special issue

1 Quantum standards and natural constants in electrical metrology

LIU Min , TU Zhiguo , PAN Pan

2024(1). DOI: 10.11823/j.issn.1674-5795.2024.01.02

[Abstract](978) [HTML](267) [PDF 1.15 M](939)

Abstract:
Introducing the role of Coulomb's law and Ampere's law in the electrical system of units. According to the principle of equivalence between mechanical power and electric power, the current unit ampere（A） is selected as the basic physical unit. The practical unit system and electrical physical measurement standards are introduced. The principles of three quantum standards of electrical measurements and the ways for tracing to the natural constant are described. The role of vacuum permeability in the formulation of the Ampere's law is analyzed. The problem of the compatibility of an electrical quantum triangle with Ohm's law is explored. It is pointed out that the elementary charge constant is not simply derived from the Josephson constant K_J-90 and the Von Klitzing constant R_H-90, but is calculated from the fine structure constant formula. The principle of conservation of energy is the first principle in the system of units, and it is the link between mechanical and electrical measurement units. It is proposed that the displacement current between quantum dots has some influence on the single electron tunneling pump, the vacuum permeability is no longer an ideal constant, and the change of vacuum permeability will be the focus of later theoretical research.

2 Localized electron beam inspection equipment for yield monitoring in integrated circuits manufacture

JIANG Junhai , SUN Weiqiang , WANG Zhen , HAN Chunying , MENG Qinglang , YU Zongqiang

2023(1):169-174. DOI: 10.11823/j.issn.1674-5795.2023.01.17

[Abstract](1164) [HTML](252) [PDF 1.18 M](1566)

Abstract:
Electron beam inspection equipment plays an important role in the yield monitoring of integrated circuits (IC) manufacture. Combining technologies of scanning electron microscopy, high-precision motion control, high-speed image processing and automatic defect classification, this equipment can inspect physical and electrical defects on IC wafers in IC manufacturing processes. In order to fill in the blank of localization, our team has independently developed the equipment. Key technical breakthroughs in high-resolution large field scanning imaging, 3D high-precision positioning with compensation, AI-assisted defect capture and classification have been made. The localized electron beam inspection equipment have already been developed and used in IC manufacture. This will accelerate the development of IC inspection technology in China.

3 Analysis and evaluation of measurement uncertainty of input resistance of data acquisition systems

LIANG Zhiguo , FENG Xiujuan

2023(5). DOI: 10.11823/j.issn.1674-5795.2023.05.14

[Abstract](763) [HTML](213) [PDF 1.54 M](1377)

Abstract:
Aiming at the problem of large measurement errors in input resistance, the physical mechanism and practical reasons were analyzed. Several main factors affecting the uncertainty of input resistance measurement were discussed, including standard voltage, measurement voltage, standard resistance value and error, and so on. The main measures to reduce the uncertainty of input resistance measurement were given, that is, the closer the value of standard resistance and input resistance, the better, and the two should be in the same order of magnitude, moreover, the difference between two different excitation voltages should be as large as possible. The evaluation results of input resistance measurement uncertainty are provided through an example, and both the correctness and feasibility of the process are proved.

4 Uncertainty evaluation of AC common mode rejection ratio measurement by RMS method

LIANG Zhiguo , FENG Xiujuan

2023(2). DOI: 10.11823/j.issn.1674-5795.2023.02.04

[Abstract](859) [HTML](323) [PDF 746.89 K](1049)

Abstract:
In order to solve the problem of common mode interference that affects the accuracy of data acquisition system in industrial field, the manifestation of AC common mode interference is studied by means of waveform analysis, and its typical characteristics of DC offset superimposed AC fluctuation and background noise are revealed. It is proposed to characterize the interference intensity by the amplitude of the effective value of the waveform, and quantitatively express the common mode rejection ratio (CMRR). At the same time, the effect of the system background noise is eliminated by using the effective value superposition model, which improves the measurement accuracy of the common mode rejection ratio. Based on this method and process, the main sources of uncertainty, such as signal source error, data acquisition system gain error, amplitude measurement error, amplitude resolution error and measurement repeatability, are discussed. The measurement uncertainty is analyzed and evaluated. Combined with an example, the uncertainty evaluation result of channel CMRR is given, and the practicability and feasibility of the method is verified.

5 Automatic calibration system for handheld digital multimeter based on visual recognition technology

HOU Yi , CHAI Yanli , WANG Jiankun , TANG Bin

2023(2). DOI: 10.11823/j.issn.1674-5795.2023.02.15

[Abstract](929) [HTML](340) [PDF 6.71 M](1263)

Abstract:
In order to solve the problem that the calibration of widely used handheld digital multimeters still relies on manual work, according to JJF 1587-2016 "Calibration Specification for Digital Multimeter", an automatic calibration device for hand-held digital multimeter is designed. The calibration device realizes the position control, function, range switching and motion control of the hand-held digital multimeter through the electromechanical system. The data reading of hand-held digital multimeter is realized through the visual recognition system. Combined with calibration software, 8-station continuous automatic calibration is realized. It is verified through test that the device improves the calibration efficiency of handheld digital multimeter and can meet the calibration requirements of handheld digital multimeter.

6 Electro-optic frequency combs: theory and applications

CHEN Caixin , LI Sixuan , YAN Ming , ZENG Heping

2026, 46(1):33-54. DOI: 10.11823/j.issn.1674-5795.2026.01.03

[Abstract](239) [HTML](124) [PDF 18.17 M](397)

Abstract:
This paper introduces the fundamental principles and classifications of optical frequency combs, reviews the generation mechanisms and representative architectures of electro-optic frequency combs (EOFCs), and systematically summarizes implementation approaches and performance characteristics of EOFCs on emerging material platforms, including thin-film lithium niobate (TFLN) and silicon nitride (SiN), covering schemes based on Mach-Zehnder modulators, phase modulators and micro-resonator modulator. Methods for spectral extension of EOFCs are discussed, followed by an overview of EOFC applications in spectroscopy, precision ranging, and optical communications. Finally, future development directions are outlined, emphasizing that interdisciplinary integration and co-design can further reduce control complexity, noise sensitivity, and thermal drift, while improving accuracy, environmental robustness, and frequency-stabilization performance, thereby accelerating the practical deployment of EOFCs in precision ranging and coherent communications.

7 Circuit fault diagnosis methods of dewpoint measurement system based on ISSA-SVM

TU Yiwei , WANG Guohua , CUI Jianmin , BAI Xuesong , NIE Jing

2023(5). DOI: 10.11823/j.issn.1674-5795.2023.05.02

[Abstract](893) [HTML](212) [PDF 1.95 M](1413)

Abstract:
Aiming at the problem of circuit fault diagnosis in high-precision resonant dewpoint measurement system, this paper proposes a circuit fault diagnosis model based on improved sparrow search algorithm (ISSA) to optimize the parameters of intelligent classifier. The support vector machine (SVM) suitable for small samples and nonlinear problems is selected as the intelligent classifier. In order to solve the problems of slow convergence speed and being easy to fall into local optima of sparrow search algorithm, an improved optimization algorithm is proposed and used to optimize the parameters of SVM, and the ISSA-SVM fault diagnosis model is constructed for resonant circuit fault diagnosis. The experimental results show that the fault diagnosis accuracy rate can reach 88.9 % on the established circuit, and the ISSA-SVM classifier can be used as a high precision resonant dewpoint sensor circuit fault diagnosis method.

8 Electric field sensing technology based on Rydberg atoms

CHEN Xuehua , CONG Nan , LUO Wenhao , ZHANG Xiaonan , WANG Yanhua , WEI Xiaogang , YANG Renfu

2023(4). DOI: 10.11823/j.issn.1674-5795.2023.04.06

[Abstract](1793) [HTML](392) [PDF 3.40 M](6612)

Abstract:
This article summarizes the basic principles of electric field sensing technology based on Rydberg atoms, and analyzes the advantages of Rydberg atomic electric field measurement, such as high sensitivity, broadband, traceability to the International System of Units (SI), and high spatial resolution. The effects of laser parameters, detector noise, environmental electromagnetic interference, and other factors on the sensitivity and frequency response bandwidth of Rydberg atomic field strength measurement were discussed. Methods to improve the sensitivity of field strength measurement, such as frequency modulation, re pumping, and parameter optimization, were introduced, and methods to enhance the frequency response bandwidth of measurement, such as single auxiliary field atomic heterodyne method and double auxiliary five level heterodyne method, were elaborated. Explored the application of Rydberg atomic electric field sensing technology in metrology, communication, radar, imaging, and other fields, and pointed out that the sensitivity of Rydberg atomic electric field measurement should be further improved by optimizing the atomic gas chamber structure, designing high-performance photodetectors, and improving the performance of optical cavities; We should conduct in-depth research on the sources of uncertainty in the measurement of the Rydberg atomic electric field, and conduct comprehensive testing and characterization of the Rydberg atomic sensor; The miniaturization and engineering design research of the Rydberg atomic electric field measurement related devices should be carried out to further improve the practical application performance of the Rydberg atomic electric field measurement technology.

9 Search for exotic force and axionlike dark matter with atomic magnetometry

ZHAO Yixin , LIU Xiyu , YU Dongrui , XIAO Wei , PENG Xiang , WU Teng , GUO Hong

2023(4). DOI: 10.11823/j.issn.1674-5795.2023.04.01

[Abstract](1150) [HTML](294) [PDF 1.92 M](1498)

Abstract:
This article provides a brief overview of the theoretical models of anomalous interactions and axionlike dark matter. It reviews the technical approaches of domestic and foreign researchers in recent years, including atomic magnetometers and comagnetometers, for exotic spin-dependent forces detection and dark matter searches. The article summarizes the experimental results regarding spin-velocity dependent interactions, spin-gravity interactions, and the coupling strength between the gradient of axionlike dark matter field and nucleons. On this basis, it provides an outlook for the future development direction in this field. By analyzing and suppressing systematic errors, and exploring new experimental schemes, it is expected to provide more stringent constraints for the coupling parameter space of spin-dependent forces, and to establish more rigorous limits of the coupling between axionlike dark matter and standard model fermions within a broader mass range.

10 Magnetometry based on nitrogen-vacancy center in diamond

JING Ke , XIE Yijin , LAN Ziheng , RONG Xing , DU Jiangfeng

2023(4). DOI: 10.11823/j.issn.1674-5795.2023.04.02

[Abstract](1486) [HTML](364) [PDF 27.33 M](1201)

Abstract:
Magnetometry is an indispensable technology in human society. Magnetometers based on quantum sensing technologies have been developed in many quantum systems to realize high spatial resolution and sensitivity. Nitrogen-vacancy (NV) center in diamond is one of the quantum systems. This article provides an overview of the precision magnetic measurement technology based on the NV center system and its applications in various fields. Principles and advantages of using the NV center for magnetic field measurement are included in this paper. The research status of the magnetometry is also presented. Besides, practical applications of the magnetometry based on NV center in the field of materials imaging and life sciences are demonstrated. In the future, the magnetometry based on NV center will play an important role in the development of high sensirivity and spatial resolution vector magnetometer and facilitate more applications as geomagnetic mapping, nondestructive testing and others

11 Quantum fundamentals of atomic magnetometer

LI Sheng , ZHOU Chao

2023(4). DOI: 10.11823/j.issn.1674-5795.2023.04.07

[Abstract](1359) [HTML](294) [PDF 531.31 K](2040)

Abstract:
Atomic magnetometer is a precision measurement instrument based on quantum technology. Due to its extensive application potential, it is becoming the domestic and worldwide cutting-edge research. Atomic magnetometer concerns many quantum theories, and a grasp of the basics is helpful to carrying out the magnetometer related work and going in for a deeper research in the related areas. The author summaries some of the elementary quantum physics involved in the atomic magnetometer, including optical pumping, light shift, optical detection, evolution of atomic polarization in magnetic field, and magnetic resonance, etc.

12 Research on low frequency expansion of magnetoelectric vibration sensors based on lag compensation method

JIAO Liang

2024, 44(3). DOI: 10.11823/j.issn.1674-5795.2024.03.08

[Abstract](652) [HTML](222) [PDF 4.42 M](912)

Abstract:
To improve the response performance of magneto electric vibration sensors in the low frequency range, a low-frequency extension method for magneto electric vibration sensors based on hysteresis compensation is proposed. Firstly, the working principle and mathematical model of the magneto electric vibration sensor were analyzed to identify the key parameters that affect the low-frequency measurement performance of the sensor. Then a second-order hysteresis compensation circuit was designed, a low-frequency compensation filtering link was introduced to optimize the transfer functions of input and output, and MATLAB software was used for simulation verification. Finally, a vibration comparison testing system was established for experimental verification. The results showed that the low-frequency extension method of magneto electric vibration sensor based on hysteresis compensation can extend the measurement bandwidth of a magneto electric vibration sensor with a natural frequency of 2.02 Hz to 0.202 Hz, verifying the feasibility of this method and providing important technical support for promoting the application of small magneto electric vibration sensors in low-frequency measurement scenarios.