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Production sequence of Si-spheres and interferometrical determination of the sphere volume

Interferometry on Prismatic Bodies

Working Group 5.44


In order to realize the length of material measures with the highest possible precision, special imaging interferometers have been (and continue to be) developed, constructed and operated. Measurements of absolute length, which is dependent on temperature and measurement time, make it possible to investigate the thermal expansion and long-term stability of materials with a very high degree of precision. Here, our aspiration is to gain ever-greater control over the sub-nanometer range in order to meet the demands of industry for decreasing tolerances.

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The primary focus of our work in research and development is on the further development of imaging interferometry; here, our goal is to be able to measure the length of prismatic material measures with increasing precision in order to meet demand. The knowledge gained in this way is beneficial for the services offered by WG 5.44 within the scope of special measurements, and forms the foundation for ongoing improvements to the interferometer of WG 5.43, “Interferometric Calibration of Gauge Blocks”. Furthermore, recently developed interferometers such as the Ultra-Precision Interferometer are available for testing material properties such as thermal expansion and long-term response; these measuring devices are the only ones of their kind in the world.

External Projects in which PTB is involved



EMRP, Research Project: JRP NEW09 METCO "Metrology of electrothermal coupling for new functional materials technology", WP3: "High Accuracy Absolute Length Measurement of Electromechanical and Thermoelastic Coupling", WP-Leiter: G. Bartl, Bearbeitung: T. Quast

EMRP, Research Project: JRP IND13 T3D “Thermal design and time-dependent dimensional drift behaviour of sensors, materials and structures", WP2: "Time and temperature dependent behaviour of materials, structures, sensors and joints ", WP-Leiter: R. Schödel, Bearbeitung: H. Lorenz

ESA-Projekt 4000101042/10/NL/PM: "Characterisation of Ultra-Stable Materials at Cryogenic Temperature; Teil 2", Projektleiter: R. Schödel, Bearbeitung: T. Middelmann

Industrieprojekt mit Ohara Inc. Japan: "Einfluss von Bearbeitungsprozessen auf die Langzeit-Stabilität von Glaskeramiken: Teil 4 ", Projektleiter: R. Schödel

PTB-Projekt im Rahmen des Größtgerätes "Beidseitig antastendes Interferometer zur Messung der absoluten Länge von Endmaßen", Projektleiter: R. Schödel, Bearbeitung: K. Rau

ESA-Projekt 4000101042/10/NL/PM: "Characterisation of Ultra-Stable Materials at Cryogenic Temperature: Teil 1", Projektleiter: R. Schödel, Bearbeitung: A. Walkov, G. Bartl, M. Zenker



Promotionsstipendium der Ägyptischen Mission / PTB-Doktorandenprogramm: "Beidseitig antastendes Interferometer zur Messung der absoluten Länge von Endmaßen; Prototyp", Projektleiter: R. Schödel, Bearbeitung: A. Abdelaty

Industrieprojekt mit SEMATECH INTERNATIONAL"Untersuchung verschiedener Substratmaterialien für die EUV-Lithographie", Projektleiter: R. Schödel

Industrieprojekt mit OHARA Inc., Japan: "Wissenschaftliche Zusammenarbeit auf dem Gebiet der Langzeitstabilität von Glaskeramik", Projektleiter: R. Schödel

Industrieprojekt mit Berliner Glas KgaA: "Einfluss der Probenpräparation auf die thermischen Ausdehnungseigenschaften verschiedener Materialien", Projektleiter: R. Schödel

Industrieprojekt mit Zeiss SMC und Schott AG "Ein Messgerät zur Messung des thermischen Ausdehnungskoeffizienten (CTE) von hochkonstanten Materialien für die EUV-Lithographie", Projektleiter:  U. Sterr, R. Schödel

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Special measurements on the thermal expansion response of materials in the temperature ranges from 10 °C to 40 °C and from 10 K to around 300 K are available on request.

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·       The most important publications of AG 5.44: Publikationen (in German)

·       These and other publications can be found in our database: PTB-Publica (in German)

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