- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Frequency pair model for selection of signal spectral components to determine position of zero optical-path difference in a pulse-train interferometer
摘要： High-accuracy measurement using phase information of fringe patterns – that is not much affected by amplitude noises – than amplitude information, in a pulse-train interferometer is demonstrated in this study. However, the selection criteria for spectral components of the measured interferogram for regeneration of phase information are not obvious. In this work, a frequency pair model is proposed. The experimental work demonstrates the model’s ability to optimally select signal components. The application field of pulse-train or white-light interferometers may be extended by associating them with the proposed method.
关键词： Metrology,Fringe analysis,Interferometry,Fourier optics and signal processing,Instrumentation, measurement, and metrology
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Scaling of Mass and Force Using Electrical Metrology
摘要： The impending redefinition of the International System of Units (SI) allows realization of the kilogram using electrical metrology. It can be shown that electrical metrology can also be used to scale mass using electrostatic forces. An approach to mass metrology at the milligram scale using an Electrostatic Force Balance (EFB) is described. The relative uncertainty in EFB mass measurements is found to be substantially lower than those obtained with the current method based on subdivision of the artifact kilogram.
关键词： capacitance,metrology,force,voltage,standards
更新于2025-09-10 09:29:36
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Quantum-enhanced sensing using non-classical spin states of a highly magnetic atom
摘要： Coherent superposition states of a mesoscopic quantum object play a major role in our understanding of the quantum to classical boundary, as well as in quantum-enhanced metrology and computing. However, their practical realization and manipulation remains challenging, requiring a high degree of control of the system and its coupling to the environment. Here, we use dysprosium atoms—the most magnetic element in its ground state—to realize coherent superpositions between electronic spin states of opposite orientation, with a mesoscopic spin size J = 8. We drive coherent spin states to quantum superpositions using non-linear light-spin interactions, observing a series of collapses and revivals of quantum coherence. These states feature highly non-classical behavior, with a sensitivity to magnetic fields enhanced by a factor 13.9(1.1) compared to coherent spin states—close to the Heisenberg limit 2J = 16—and an intrinsic fragility to environmental noise.
关键词： Heisenberg limit,Dysprosium atoms,Quantum-enhanced sensing,Non-classical spin states,Quantum metrology
更新于2025-09-10 09:29:36
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Historical overview of Ramsey spectroscopy and its relevance on Time and Frequency Metrology
摘要： A brief overview of the historical evolution of the method of successive oscillatory fields developed by Norman Ramsey, and some different implementations of the decurrent methodology are presented. We use time and frequency standards, from Cs atomic beams to optical standards, as examples. The scientific progress and the technological implementation achieved through a partnership between USP-SC and INMETRO are shown on the characterization of each time and frequency standard.
关键词： optical standards,Cs atomic beams,Ramsey spectroscopy,atomic clocks,Time and Frequency Metrology
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE International Symposium on Precision Clock Synchronization for Measurement,Control, and Communication (ISPCS) - Geneva, Switzerland (2018.9.30-2018.10.5)] 2018 IEEE International Symposium on Precision Clock Synchronization for Measurement, Control, and Communication (ISPCS) - Time and Frequency Distribution over fibre for Geodesy, Seismology and Industry
摘要： The Italian Institute of Metrology (INRIM) realized a fibre-optic backbone, 1850 km long, for the dissemination of accurate time and frequency standards. Moreover, we implemented a dedicated service for time distribution with traceability to UTC for industrial users. Here we describe techniques, architectures and results.
关键词： atomic clocks,time/frequency metrology,fibre-optic link
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Design of Digitized Control and Zero Boil-Off Cryogenic Container for CCC inNIM
摘要： As a key instrument for resistance metrology, cryogenic current comparator (CCC) is now widely used in national labs. In order to further improve the performances of CCC and make it easy operate, NIM has made some improvements, which are developing digital controller to replace conventional analog circuit and designing a zero boil-off cryogenic container specially served for CCC. Pre-experiments show that the new digital controller performs a better operability and the zero boil-off cryogenic container has a significant convenience for CCC cryo maintenance.
关键词： metrology,Cryogenic current comparator,digital control,zero boil-off,resistance measurement
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - One-Gate Ratchet Single-Electron Pump: Device Failure Mechanisms
摘要： Electrical current standards based on the charge of the electron will become more important after the SI redefinition. Many of the best recent charge pump results have come in the one-gate ratchet pumping mode, but this mode is sometimes difficult to achieve. In this work, we discuss the likely reasons for this difficulty, and ways to overcome the difficulty.
关键词： single-electron metrology,One-gate ratchet charge pump,device failure mechanisms
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Epitaxial Graphene for High-Current QHE Resistance Standards
摘要： We report the growth of large-area monolayer graphene on the centimeter scale using an optimized growth process and morphology improvements. Magneto-transport measurements on graphene quantum Hall effect devices demonstrate the applicability for high-current quantum resistance metrology.
关键词： polymer-assisted growth (PASG),face-to-graphite (FTG),epitaxial graphene,quantum resistance metrology
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Application of Monte Carlo Method in Uncertainty Analysis of Mismatch Factor
摘要： When calibrating with the direct comparison method, the source reflection coefficient can be calculated by using the scattering parameters of the three-port device, and the mismatch factor and its uncertainty can be calculated by Monte Carlo method (MCM). Moreover, compared to the common method used by calibration laboratories that assuming the mismatch factor as 1, MCM will greatly reduce the uncertainty introduced by mismatch.
关键词： Monte Carlo method,Direct comparison method,Microwave power,Metrology
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Electromagnetic Metrology for NEMS
摘要： This paper outlines how demands on electromagnetic metrology have developed over recent years with the continuing reduction in the typical length scale of electronic components and circuits. In addition novel materials, especially 2D self-supporting structures such as graphene, have properties quite unlike conventional systems. At the nanoscale radical changes occur in techniques required and even in the physical quantities measured. This paper focusses on the example of a near-field scanning microwave microscope and its application to nanoelectromechanical system resonators to illustrate these changes and challenges.
关键词： nanoscale electromagnetic metrology,NEMS,graphene,microwave,NSMM
更新于2025-09-10 09:29:36