Digital frequency offset-locked He-Ne laser system with high beat frequency stability, narrow optical linewidth and optical fibre output. - In: Measurement science and technology, ISSN 1361-6501, Bd. 29 (2018), 6, S. 064013, insges. 13 S.
https://doi.org/10.1088/1361-6501/aab987
The Planck-Balance - using a fixed value of the Planck constant to calibrate E1/E2-weights. - In: Measurement science and technology, ISSN 1361-6501, Bd. 29 (2018), 7, S. 074003, insges. 9 S.
https://doi.org/10.1088/1361-6501/aabc9e
State of the art precision motion systems based on compliant mechanisms. - In: The 4th International Conference Mechanical Engineering in XXI Century, (2018), S. 3-8
High-precision angle sensor based on a Köster's prism with absolute zero-point. - In: Measurement science and technology, ISSN 1361-6501, Bd. 29 (2018), 6, S. 064006, insges. 12 S.
https://doi.org/10.1088/1361-6501/aab252
Investigation into the limitations of straightness interferometers using a multisensor-based error separation method. - In: Measurement science and technology, ISSN 1361-6501, Bd. 29 (2018), 6, S. 064001, insges. 14 S.
https://doi.org/10.1088/1361-6501/aab7e3
Field-emission scanning probe lithography with self-actuating and self-sensing cantilevers for devices with single digit nanometer dimensions. - In: Novel Patterning Technologies 2018, (2018), 1058406, 13 Seiten
https://doi.org/10.1117/12.2299955
How to drive an optical measurement system to outstanding performance?. - In: Ultra-High-Definition Imaging Systems, (2018), 105570Q, insges. 15 S.
In the context of measurement technology, optical methods have a number of unique features. These features include in particular the non-contact and high speed interaction with the object under test, the largely free scalability of the dimension of the probing tool, the high resolution of the data, the diversity of information channels in the light field, and the flexible adaptability of the comparative standard - the wavelength. On the other hand the user is confronted with a number of serious challenges. Two of the biggest challenges that currently attract high attention in both the technical as well as life sciences, relate to exceeding the physical limits of resolution and to improve the precision of the measurement. Therefore optical measurement methods are subject to constant improvement. The characteristics that give rise to improve the performance of the systems are obviously dependent on the purpose of the measurement and the object under test. But there are also general features that can be used to assess the performance of a measurement system. Here we refer to the spatial and temporal resolution, the area related resolution, the precision and trueness of the results, the robustness, the degree of automation, the process capability and the ability to work as close as possible to the process. In this contribution we describe the current challenges for measurement systems. Based on this we discuss general and application dependent features for the assessment of modern optical measurement systems. Afterwards, we describe measures to assess and to improve their performance. Finally, we show an advanced optical measurement system where several of these features were considered with regard to ensuring a high performance.
https://doi.org/10.1117/12.2300856
Development of laser positioning system of high accuracy in the nanometer range. - In: Advanced Fabrication Technologies for Micro/Nano Optics and Photonics XI, (2018), 105440E, insges. 7 S.
Direct Laser Writing techniques like two-photon-polymerization or UV-lithography have become common tools for the micro- and nanofabrication of precise devices like photonic crystals. A decrease in the size of structures of special devices requires a significant better resolution of the laser beam system that can be determined by using different photoinitiators or a second depletion laser for STED-lithography. However, besides the optical limits for the resolution of the laser system due to diffraction effects, the positioning systems for the laser beam or the sample stage lead to further imprecisenesses. To benefit from the high resolution techniques for the structuring process, the need for highly accurate positioning systems has dramatically grown during the last years. A combination of lithographic techniques with a nanopositioning and nanomeasuring machine NMM-1, developed at the TU Ilmenau, enables high precision structuring capability in an extended range. The large positioning volume of 25mm x 25mm x 5mm with a resolution in the sub-nanometer range is a good condition for ultra precision manufacturing with large area 3D-Laser-Lithography. Advantages and disadvantages as well as further developments of the NMM-1 system will be discussed related to current developments in the laser beam and nanopositioning system optimization. Part of the further development is an analysis of the implementability of additional ultra precise rotational systems in the NMM-1 for the unlimited addressability perpendicular to the surface of a hemisphere as key strategy for multiaxial nanopositioning and nanofabrication systems.
https://doi.org/10.1117/12.2312704
Methods for temperature determination of electrical discharges generated by opening contacts in explosive gas mixtures :
Methoden der Temperaturbestimmung von elektrischen Entladungen bei Öffnungs-Kontaktvorgängen in zündfähigen Gasen. - In: Technisches Messen, ISSN 2196-7113, Bd. 85 (2018), 1, S. 56-64
Für elektrische Entladungen, die bei niedrigen Spannungen von 20-40V und Strömen von 40-100mA nach der Öffnung eines elektrischen Kontaktes in explosiven Atmosphären auftreten, wurden erste spektroskopische Untersuchungen hinsichtlich der dabei entstehenden Temperatur durchgeführt. Diese Metalldampf-Entladungen, die ähnlich dem "kurzen Bogen" (short arc) sind, werden im international standardisierten Funkenprüfgerät gemäß IEC 60079-11 erzeugt, um die Eignung elektrischer Komponenten in explosionsgeschützten Bereichen zu beurteilen. - Die Temperatur ist bei diesen komplexen Zündvorgängen, die im Funkenprüfgerät auftreten, ein Schlüsselparameter. Einerseits ist die Temperatur der Kontaktmaterialien für die Beurteilung der zwingend erforderlichen Vorprozesse vor der Hauptentladung relevant, andererseits kann die Wirkung der Entladung durch die Elektronen-, Ionen und Gastemperatur charakterisiert werden. Dieser Artikel beschreibt den aktuellen Stand zur Temperaturmessung dieser elektrischen Entladungen, einschließlich der Herausforderungen, die dem genaueren Verständnis dieser Entladungsvorgänge und des thermochemischen Zündprozesses dienen sollen. Für Entladungen mit 30V und 100mA unter den genannten Rahmenbedingungen wurden Anregungstemperaturen im Bereich von 3500-5000K gemessen und berechnet.
https://doi.org/10.1515/teme-2017-0082
Schnelle Lufttemperaturfühler zur Anwendung in der Präzisionsmesstechnik und Maschinenkalibrierung. - In: Technisches Messen, ISSN 2196-7113, Bd. 85 (2018), 1, S. 70-75
https://doi.org/10.1515/teme-2017-0103