Fundamental Metrology Research Articles

A complete analysis of the link uncertainty budget for pulsed laser time transfer on China space station

High-precision Time-Frequency Rack (HTFR) mission, a part of experiment module II of the China Space Station (CSS), was equipped with a Sr optical clock, H-maser, and laser-cooled microwave clock. To compare time and frequency across widely separated clocks, a microwave link, and a pulsed laser link were both established, which probably enables new possibilities for fundamental science, geodesy, and metrology. Based on the existing relativistic theory for time and frequency transfer, we derive a relativistic model of satellite-ground laser time transfer on CSS (CLT), which can be of direct use in CLT data processing. In addition to first and second-order Sagnac effects, it also includes relativistic rate shifts, atmospheric refraction, and turbulence, laser retroreflector array (LRA) range correction, and position correction between detector and reflector, satisfying the stability evaluation of CSS atomic clocks with fractional frequency stability of 3 × 10−17/10000 s. Additionally, we numerically investigate the link error magnitude and use Monte Carlo simulations to assess the impact of correcting for link errors on the stability of the CLT, taking into account the CSS orbit and attitude determinations as well as the CLT payload calibration parameters. It is shown that the CLT link can be considered to reach a TDEV of approximately 0.1 ps/300 s while meeting the CSS design objectives. The primary factors that influence the stability of the CLT are the position correction between detector and reflector, LRA range correction, and the coupling relation of these two error distributions.

Legislative basis for assurance of measurement uniformity

An overview of the legal framework of metrology at the international level, in particular, the activities of the intergovernmental International Organization of Legal Metrology, is given. The establishment of the International Organization of Legal Metrology has had an impact on the consolidation of the regulatory framework for metrology at the regional level, especially in the European Union. The reliability, comparability and traceability of measurement results are ensured by international regulatory documents developed by countries in the field of activity of seven international organizations. For international recognition of measurement and test results of any country. There is a need for a system of normative instruments that ensure international law. Strategically, it is necessary to create a legal framework so that it is possible to move from regional politics to global politics. The role of legal metrology at the regional level and the formation of the legislative framework of fundamental metrology in the world are described. The article presents a database of basic documents for solving scientific problems of ensuring the uniformity of measurements at the international level and the main milestones in the history of the formation of the legal framework of the measurement system in Russia for two centuries. The creation of the metrological service of the USSR, and then the state system for ensuring the uniformity of measurements determined new approaches to improving legislation in the field of metrology. Harmonization of the language of measurements and approaches to solving the problems of metrology will ensure the uniformity of measurements not only in individual countries and regions, but also on a global scale.

Advances in Portable Atom Interferometry-Based Gravity Sensing.

Gravity sensing is a valuable technique used for several applications, including fundamental physics, civil engineering, metrology, geology, and resource exploration. While classical gravimeters have proven useful, they face limitations, such as mechanical wear on the test masses, resulting in drift, and limited measurement speeds, hindering their use for long-term monitoring, as well as the need to average out microseismic vibrations, limiting their speed of data acquisition. Emerging sensors based on atom interferometry for gravity measurements could offer promising solutions to these limitations, and are currently advancing towards portable devices for real-world applications. This article provides a brief state-of-the-art review of portable atom interferometry-based quantum sensors and provides a perspective on routes towards improved sensors.

Involvement and use of European Metrology Programme for Innovation and Research EMPIR in the Czech Metrology Institute – a positive example of the use of European cooperation

The Czech Metrology Institute (CMI) has been the national metrology institute of the Czech Republic since 1993. The significant development of the CMI's fundamental metrology departments and the gradual growth of the CMI's scientific and research capacities are linked to its successful participation in the European Metrology Research Programme (EMRP) and the European Metrology Programme for Innovation and Research (EMPIR). In total, 28 countries have participated in the EMPIR Programme, with Switzerland, Norway, Serbia, Bosnia and Herzegovina, Turkey and the UK in addition to the EU Member States. The necessary organisational and administrative background for the realisation of the EMPIR Programme was provided by EURAMET e.V., a European Regional Metrology Organisation operated as a non-profit association under German law. The most important benefit of the Programme for the CMI and the Czech Republic is the successful implementation of the research results of individual EMPIR projects. Within the framework of this implementation of the EMPIR results in the CMI, 6 new state measurement standards of the Czech Republic have already been established and another 4 are in the stage of preparation for announcement. Furthermore, 23 new or significantly modified measurement methods have been developed based on the results within the CMI and are now provided as a service by the CMI. Finally, participation in the EMPIR projects has been used to train 42 new CMI scientists in various fields of measurement. If to add to this the use of the results of the former EMRP Programme, it can be concluded that the development of metrology at the CMI over the last 10 years has been strongly conditioned by successful participation in European Metrology Programmes and the ability of the CMI to subsequently apply the results of individual projects to its laboratory practice.

Giant photonic spin Hall effect empowered by polarization-dependent quasibound states in the continuum in compound grating waveguide structures

The photonic spin Hall effect (PSHE) plays an important role in both fundamental science and precision metrology. In this paper, we theoretically propose a polarization-dependent bound state in the continuum (BIC) in a compound grating waveguide structure based on the selectable guided resonance at near-infrared wavelengths. Empowered by the unique resonant property and polarization-dependent property of the quasi-BIC, the transverse shift of the PSHE can be intensively enhanced to the order of hundreds of micrometers. Besides, the enhancement of the transverse shift of the PSHE is robust against the geometric parameters. Our work not only provides an all-dielectric platform to achieve giant PSHE, but also offers a viable approach to design high-performance PSHE-based optical devices.

Preface

Selected papers from the 25th edition of the International Conference on Spectral Line Shapes (ICSLS 2022) The 25th edition of the International Conference on Spectral Line Shapes (ICSLS 2022) was held inside the wonderful Monumental Complex of Belvedere di San Leucio, in Caserta, south of Italy, from 19 to 24 June 2022. Initially scheduled for June 2020, it was postponed by two years due to the COVID-19 pandemic.ICSLS 2022 has brought together, in person, researchers from universities and institutions to stimulate new activities in those fields in which the analysis of spectral line shapes is of the utmost importance, including atomic and molecular physics, precision spectroscopy and fundamental metrology, plasma physics, astronomical spectroscopy, spectroscopy of planetary atmospheres and exoplanets, applications of spectroscopy to environmental, medical and industrial domains. There have been roughly 70 participants from 18 different countries, including Brazil, England, France, Germany, Ireland, Israel, Italy, Japan, Latvia, Poland, Sweden, and USA. The scientific programme of the Conference consisted of 17 invited lectures, 28 selected talks and 29 poster presentations organised into two poster sessions. All contributions were distributed among the following seven Sessions:- Fundamental tests and measurements;- Laboratory and astrophysical plasmas;- Line shape theory and experiments;- Innovative methods;- Environmental spectroscopy;- Molecular parameters;- Earth and Planetary atmospheres.Regardless of the Session, the average quality of the presentations was very high.List of 25th International Conference on Spectral Line Shapes, International Program Committee, Local Organising Committee are available in this pdf.

Significance of Fundamental Metrology of 3D-Printed Parts for Engineering Design: Dimensional Accuracy

This paper discusses some basic metrology considerations when 3D printing. The importance of ensuring correct measurements is highlighted especially for practical applications. The last part of the paper presents sample dimensional measurements of 3D-printed parts with varying sizes, infill density and layer thickness. Different cube sizes of 10 mm3, 15 mm3, and 20 mm3 has been produced using a commercially-available 3D printer. Acrylonitrile butadiene styrene (ABS) has been used for the experiments. Important observations and insights are presented.

Laser Cooling of a Lattice Vibration in van der Waals Semiconductor.

Laser cooling atoms and molecules to ultralow temperatures has produced plenty of opportunities in fundamental physics, precision metrology, and quantum science. Although theoretically proposed over 40 years, the laser cooling of certain lattice vibrations (i.e., phonon) remains a challenge owing to the complexity of solid structures. Here, we demonstrate Raman cooling of a longitudinal optical phonon in two-dimensional semiconductor WS2 by red-detuning excitation at the sideband of the exciton (bound electron-hole pair). Strong coupling between the phonon and exciton and appreciable optomechanical coupling rates provide access to cooling high-frequency phonons that are robust against thermal decoherence even at room temperature. Our experiment opens possibilities of laser cooling and control of individual optical phonon and, eventually, possible cooling of matter in van der Waals semiconductor.

Mid-infrared broadband optical frequency comb generated in MgF2 resonators

Microresonator-based optical frequency combs are broadband light sources consisting of equally spaced and coherent narrow lines, which are extremely promising for applications in molecular spectroscopy and sensing in the mid-infrared (MIR) spectral region. There are still great challenges in exploring how to improve materials for microresonator fabrication, extend spectral bandwidth of parametric combs, and realize fully stabilized soliton MIR frequency combs. Here, we present an effective scheme for broadband MIR optical frequency comb generation in a MgF 2 crystalline microresonator pumped by the quantum cascade laser. The spectral evolution dynamics of the MIR Kerr frequency comb is numerically investigated, revealing the formation mechanism of the microresonator soliton comb via scanning the pump-resonance detuning. We also experimentally implement the modulation instability state MIR frequency comb generation in MgF 2 resonators covering from 3380 nm to 7760 nm. This work proceeds microresonator-based comb technology toward a miniaturization MIR spectroscopic device that provides potential opportunities in many fields such as fundamental physics and metrology.

Fundamental Physical Constants: Search Results and Variation Descriptions

We consider the current results in search for and description of temporal variations of fundamental physical constants (FPCs) obtained under laboratory and astrophysical conditions. On the basis of fixed values of base constants, those FPCs have been chosen that can exhibit variations of greatest interest from the viewpoints of physics and metrology. An analysis of the current data concerning these constants is performed, and estimates of their variations on large time scales are presented. We point out the significance of studying long-term FPC variations for both practical and fundamental metrology.

Detecting momentum weak value: Shack-Hartmann versus a weak measurement wavefront sensor.

The task of wavefront sensing is to measure the phase of the optical field. Here, we demonstrate that the widely used Shack-Hartmann wavefront sensor detects the weak value of transverse momentum, usually achieved by the method of quantum weak measurement. We extend its input states to partially coherent states and compare it with the weak measurement wavefront sensor, which has a higher spatial resolution but a smaller dynamic range. Since weak values are commonly used in investigating fundamental quantum physics and quantum metrology, our work would find essential applications in these fields.

Compact cold atom gravimeters and precise gravity measurement

Atomic gravimetry measures the gravitional acceleration of an ensemble of identical neutral atoms through the atom interferometry based on Raman two-photon transition, where the Raman lasers are used as “optical ruler" and the identical neutral atoms play the role of test mass and quantum storage of gravity field information. As the novel gravimetry system suffers no mechanical wear and works at a higher repetition rate, atom gravimetry can reach a much better short-term sensitivity than the classical falling-corner-cube counterpart, and the accuracy is reasonably well. Since the very first in-laboratory device built over 30 years ago, atomic gravimetry has matured to a versatile tool that offers both precise and accurate absolute gravity measurement to fundamental research and metrology, such as testing the weak equivalence principle or linking the mass and weight of the test mass in Watt (Kibble) balance. As the current rapid development of compact cold-atom gravimeters, atomic gravimetry is moving out of the laboratory to be used as a quantum enhancement of classical devices in dynamical measurement, such as geophysics survey, inertial navigation and space mission. We review the roadmap for the development of cold-atom absolute gravimetry, highlight recent advances in the dynamical measurement using compact cold atom gravimeters and discuss the associated technological challenges. In the future, with the maturity of its application in dynamical measurement or civil engineering and the innovation in atom interferometry theory, atomic gravimetry could play a more and more important role in our life.

Accurate Characterization of High-$Q$ Microwave Resonances for Metrology Applications

Microwave resonators are widely adopted as high sensitivity sensors in both applied and fundamental metrology, to measure a number of different physical quantities, such as temperature, humidity, pressure, length and material properties. High sensitivity, and thus potential high measurement precision and accuracy, can be achieved by resorting to high-quality-factor (Q) resonators. Nonetheless, in order to accurately measure a high-Q resonance and obtain low measurement uncertainty, as required by metrology applications, the entire measurement set-up must be carefully designed. This papers presents an overview of resonance frequency measurements for metrology applications, illustrating the various aspects and issues to be dealt with when pursuing highly accurate measurements, as well as of the most relevant achievements in this field.

Approbation of the Laser Doppler Anemometer Lad-08 on the Secondary Standard Test Rig for Air Flow Speed

In the field of fundamental metrology and ensuring the unity of measuring instruments, the role of optical information methods, systems and technologies of non-contact diagnostics of dynamic processes is extremely relevant. The profiles of the axial velocity component were measured in the working section of the secondary standard test rig for air flow speed. The flow kinematics inside the working section is studied using a laser Doppler anemometer (LDA) with an adaptive temporal selection of the velocity vector (LAD-08).

Materials of the XII International Scientific and Technical Conference "METROLOGY AND MEASURING TECHNIQUES" ("METROLOGY-2020")

This special issue of the Ukrainian Metrology Journal is dedicated to the the XII International Scientific and Technical Conference METROLOGY AND MEASURING TECHNIQUES (METROLOGY-2020). It presents theses of reports on the Reproduction and distribution of SI units, Fundamental metrology and traceability, Results of international comparisons, Standards and measuring systems, Sensors, Sensors and Intelligent Systems Technologies, Industry 4.0 and additive technology, Computer modeling for metrology needs, Metrology to improve the efficiency and reliability of energy systems and networks, New documents and standards in metrology, legal metrology. International Scientific and Technical Seminar Uncertainty of Measurements: Scientific, Applied, Regulatory and Methodological Aspects (UM-2020) was held within the framework of the conference.

Trapping, Cooling, and Photodissociation Analysis of State-Selected H2+ Ions Produced by ( 3+1 ) Multiphoton Ionization

We report on the production of cold, state-selected H$_2^+$ molecular ions in a linear RF trap. The ions are produced by (3+1) resonance-enhanced multi-photon ionisation (REMPI) of H$_2$, and sympathetically cooled by laser-cooled Be$^+$ ions. After demonstrating and characterizing the REMPI process, we use photodissociation by a deep UV laser at 213~nm to verify the high vibrational purity of the produced H$_2^+$ ion samples. Moreover, the large difference between the photodissociation efficiencies of ions created in the $v=0$ and $v=1$ levels provides a way to detect a $v=0 \to 1$ transition. These results pave the way towards high-resolution vibrational spectroscopy of H$_2^+$ for fundamental metrology applications.

Possible expanding of the metrology object on the example of industrial enterprises management assessment

Metrology has given the necessary driving force to the second industrial revolution. However, the widespread use of business solutions based on information technologies allows to talk about reducing mass production in favor of individual production. Accordingly, the consequences for metrology are the need to expand the object. The definition and subject of metrology do not contradict this transformation. The axioms of fundamental metrology can be slightly changed on the example of the assessment of industrial enterprises management for the possibility of expanding the metrology object.

A consistent unified framework for the new system of units: Matter–wave optics

Abstract Thanks to considerable progress in quantum techniques, it has been possible to redefine all SI base units from fundamental constants. A last challenge is to produce a unified framework for fundamental metrology in which all base quantities and relevant fundamental constants appear naturally and consistently. We suggest a generalized 5D framework in which both gravito-inertial and electromagnetic interactions have a natural geometrical signification and in which all measurements can be reduced to phase determinations by optical or matter–wave interferometry. The corner stones of this unification are action and entropy. The connection is made with Kaluza's 5D theory and Planck's natural units.

Fundamental Metrology. The Magnetic-Field Theory of Measurements with Use of the Phenomenon of Transfer of Energy and Information through Material or Substance. Part I. Philosophical Aspects of the Theory

Philosophical aspects of magnetic-field theory of measurements are considered. Organic laws, categories, scientific principles and so on are resulted, representing the given theory as complete system of concepts and sights. The definition of magnetic-field theory of measurements is given. It is stated that there are five fundamental laws and five scientific principles which are a foundation of the created theory. The system of the purpose of the theory is stated. The developed scientific directions are highlighted.

Note: Large active area solid state photon counter with 20 ps timing resolution and 60 fs detection delay stability.

We are reporting on the design, construction, and performance of a photon counting detector system, which is based on single photon avalanche diode detector technology. This photon counting device has been optimized for very high timing resolution and stability of its detection delay. The foreseen application of this detector is laser ranging of space objects, laser time transfer ground to space and fundamental metrology. The single photon avalanche diode structure, manufactured on silicon using K14 technology, is used as a sensor. The active area of the sensor is circular with 200 μm diameter. Its photon detection probability exceeds 40% in the wavelength range spanning from 500 to 800 nm. The sensor is operated in active quenching and gating mode. A new control circuit was optimized to maintain high timing resolution and detection delay stability. In connection to this circuit, timing resolution of the detector is reaching 20 ps FWHM. In addition, the temperature change of the detection delay is as low as 70 fs/K. As a result, the detection delay stability of the device is exceptional: expressed in the form of time deviation, detection delay stability of better than 60 fs has been achieved. Considering the large active area aperture of the detector, this is, to our knowledge, the best timing performance reported for a solid state photon counting detector so far.