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Nachrichten aus dem Jahresbericht 2019

Grundlagen der Metrologie

Virtual experiments have become an indispensable tool for the design and the accuracy assessment of novel measurement procedures and instruments. Virtual experiments are particularly relevant in modern optics due to its challenging demands for highly accurate measurements. This paper introduces SimOptDevice, a flexible library for opto-mechanical virtual experiments. After describing the scope and...

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Im Rahmen der engen Zusammenarbeit zwischen Fertigung (FB 5.5) und Messtechnik (FB 4.2) in der PTB sind hochgenaue Referenzflächen gefertigt worden, die sich aus Kugelflächen zusammensetzen. Durch Rückführung der Sphärizität wurden die Referenzflächen im Rahmen des EMPIR-Projektes 15SIB01 erstmalig zur Überprüfung eines Asphären- und Freiformflächenmessgerätes verwendet.

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We report on experimental results in a new regime of relativistic light-matter interaction employing midinfrared (3.9−μm wavelength) high-intensity femtosecond laser pulses. In the laser-generated plasma, electrons reach relativistic energies already for rather low intensities due to the fortunate λ2 scaling of the kinetic energy with the laser wavelength. The lower intensity efficiently...

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The uncertainty for photometric responsivity calibrated with the tunable lasers in photometry setup (TULIP) at Physikalisch-Technische Bundesanstalt (PTB) is presented. The measurement and the uncertainty calculation presented were done in preparation for the upcoming new traceability chain for luminous intensity at PTB. Regarding the new traceability a comprehensive uncertainty calculation is...

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The assumption that the reflectance of white diffuse reflectance standards is identical to that of the perfect reflecting diffuser (PRD) allows these standards to be used to characterize reflectance or radiance factors of any surface at any irradiation/collection geometry simply by comparison. However, this assumption is only true within certain limits, and, for some applications, requirements may...

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Für eine Vielzahl von optischen Anwendungen, wie z.B. bei adaptiven Optiken in der Astronomie, der optischen Formmessung, der Ophthalmologie oder für sub-Nanometer genaue Längenmessungen ist es notwendig, optische Wellenfronten möglichst genau (besser als ë/50) zu bestimmen. Hierfür wird von der PTB und der Optocraft GmbH innerhalb eines gemeinsamen TransMeT-Projektes eine rückführbare...

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In Wissenschaft und Technik werden vermehrt große optische Flächen eingesetzt, z. B. für astronomische Teleskopspiegel und in der Optik- und Automobilindustrie. Dabei werden auch zunehmend Asphären und Freiformflächen verwendet. Dies schafft einen Bedarf an einer hochgenauen und rückgeführten Formmessung von großen Optiken.
Wir entwickeln ein Konzept für die optische Formmessung an Flächen bis zu...

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Single-photon sources have a wide field of implementation, e.g. in quantum key distribution, quantum computing, and quantum-enhanced optical measurements. Because of their negligible background and high suppression of multi-photon emission, single-photon sources have the potential to become a standard source in radiometry. Such source is necessary to close the gap between classical and quantum...

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Single-photon sources play an important role in many of the emerging quantum technologies. Beside their implementation in quantum computing and quantum key distribution [1, 2], they are also interesting for the radiometry [1]. Ideally, single-photon sources have neither multi-photon emission nor background emission. Such a source has the potential to become a standard source in radiometry [2]....

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Single-photon sources play an important role in several fields of research, e.g. in quantum key distribution and quantum-enhanced measurements. In radiometry, a single-photon source is very favorable, compared to a classical source, as a standard source for the detection efficiency calibration of single-photon detectors. Furthermore, such source is necessary to close the gap between classical and...

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Die AG 4.51 Reflexion und Transmission (https://www.ptb.de/cms/ptb/fachabteilungen/abt4/fb-45/ag-451.html) des Fachbereichs 4.5 Angewandte Radiometrie der PTB Braunschweig betreibt im Arbeitsbereich der gerichteten Reflexions- und Transmissionsmessungen eine Referenzapparatur, die einen nominellen Wellenlängenbereich von 200 nm bis maximal 20 m abdeckt. Zur Erzeugung der Messtrahlung oberhalb von...

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We present the concept of a new setup, which combines two different sampling methods to measure the modulation transfer function of camera objectives. The development process with the goal of reaching a measurement uncertainty of 0.01 (k=2) is supported by optical ray tracing simulations in addition to the geometrical modeling of the system.

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Bericht über den Stand der pränormativen Aktivitäten in CIE JTC 12 "The measurement of sparkle and graininess" und über neuartige definierte Proben zur Charakterisierung von Messapparaturen und -verfahren.

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Single-photon sources are set to be a fundamental tool for metrological applications as well as for quantum information related technologies. Because of their upcoming widespread dissemination, the need for their characterization and standardization is becoming of the utmost importance. Here, we illustrate a strategy to provide a quantitative estimate of the multi-photon component of a...

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Two-way satellite time and frequency transfer (TWSTFT) is a primary technique for the generation of coordinated universal time (UTC). At present, more than 12 timing laboratories around the world use SAtellite Time and Ranging Equipment (SATRE) modems in TWSTFT operations and contribute data for the realization of UTC. The advantages of TWSTFT are its small calibration uncertainty (≤1.0 ns if the...

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The range of possible implementations of single-photon sources in quantum information processing is rapidly growing. In order to achieve high accuracy and metrological traceability, we need reliable methods for their absolute characterization. Furthermore, single-photon emitters could be implemented as a standard source for the detection efficiency calibration of single-photon detectors. The...

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Spectroscopic Mueller matrix ellipsometry is a promising tool for the characterization of nanostruc-tured surfaces. Direct optical measurements of samples with geometrical dimensions smaller than the incident wavelength are inherently limited by the classical resolution limit. However, as an indi-rect measurement technique, this limit does not apply to ellipsometry. In this contribution, we...

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We show a novel method to derive best-fitting sample parameters and their uncertainties from measured Mueller matrices.
The nonoptimal treatment of depolarization in current approaches to evaluate Mueller matrix measurements may lead to systematic measurement errors and inadequate uncertainty estimations, particularly for surfaces with substantial depolarization. To overcome these issues, we...

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Am LENA, in Kooperation mit der TUBS und der PTB, werden nanostrukturierte GMR-Mikrofarbfilter designt, entwickelt und gefertigt. In Kombination mit CCD oder CMOS Bildsensoren sollen damit effiziente spektroskopische Sensoren für Anwendungen in Medizin und Biologie entwickelt werden. Die GMR-Farbfilter basieren auf periodischen Subwellenlängen-Metallgittern in Kombination mit einer dielektrischen...

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Solar simulators for PV modules often consist of several lamps arranged side by side to provide the irradiance necessary for PV module testing under standard test conditions. Since these simulators are no point sources, the angular distribution of the radiance emitted by the simulators can lead to systematic deviations in measured PV device’s performances. To quantify the opening angle of a solar...

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Spectral responsivity (SR) measurements are a powerful technique to measure the opto-electronic properties of photovoltaic devices like solar cells or PV modules. Although the SR determination of solar cells is a common and established technique for many years, much more effort must be taken to determine the SR of PV modules due to their size. Significantly larger and more complex solar simulator...

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Single‐photon sources (SPSs) based on quantum emitters hold promise in quantum radiometry as metrology standard for photon fluxes at the low light level. Ideally this requires control over the photon flux in a wide dynamic range, sub‐Poissonian photon statistics, and narrow‐band emission spectrum. In this work, a monochromatic SPS based on an organic dye molecule is presented, whose photon flux is...

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Die Mikrowellensynthese ist ein essentieller Bestandteil der Fontänenuhren. Mit ihr werden die für die Zustandspräparation und die Anregung des Uhrenübergangs benötigten Mikrowellensignale erzeugt. Unsicherheiten in diesem Teilsystem wirken sich direkt auf die Gesamtunsicherheit der Fontänenuhren aus. Durch Anpassungen im Synthesizer-Design wurden die Unsicherheitsbeiträge der Mikrowellensynthese...

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A round robin comparison of freeform form measurements was carried out by the project partners and stakeholders of a European metrology research project. Altogether six measuring instruments were considered: five different (pointwise and areal) optical devices and one tactile device. Three optical freeform surfaces were used for the comparison measurements, where two specimens were measured by...

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The paper presents the effect of mechanical mounting of optical reference elements on their surface shape. Optical reference surfaces are key elements when traceable, highly accurate and precise optical surface measurements are required. In order to calibrate measuring instruments and compare the metrological capabilities of different metrology institutes, universities and other stakeholders, the...

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Metrologie für die Wirtschaft

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Metrologie für die Gesellschaft

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Internationale Angelegenheiten

The Supplementary Comparison COOMET.PR-S2 was carried out to ensure the correctness and comparability of angle of rotation of plane of polarization measured by the Participants of the comparison within the uncertainties claimed for their measuring facility.
COOMET.PR-S2 was conducted within the Regional Metrology Organization (RMO) "Euro-Asian Cooperation of National Metrological Institutions"...

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