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Division 4

Division 4 which is responsible for optics is home to three base units: that of length, time and luminous intensity. On this basis, standards and measuring methods of highest accuracy are developed for various optical quantities.



Division "Optics" supports industry, science and society by providing measurement services, research and development in the field of optical technology. Based on the SI units of length, time and luminous intensity different units are realized and disseminated. Further more, accurate standards and measurement techniques are developed.

The division realizes the time scale UTC (PTB), which is the legal time in the Federal Republic of Germany, performs precision measurements in different fields of optics and cooperates in international standardisation and certification.

4 division report from the annual report 2021 (german only)4 division report from the annual report 2021 (german only)

The Opens external link in new windowdivision report provides an overview of the most important news and events of the "Optics" division of the past year and thus complements the Opens internal link in current windowannual Report 2021 of the PTB. (german only)


Atmosphärische Aerosole beeinflussen das Klima durch Wechselwirkungen mit der Sonnenstrahlung und ihre Auswirkung auf die Wolkenbildung. Die Abschwächung der Sonnenstrahlung, die die Aerosolschicht durchdringt, wird durch die Aerosol Optische Dicke (AOD) beschrieben. Die AOD wird aus atmosphärischen Transmissionsmessungen bestimmt, wobei die Sonne als Quelle dient. Die Messungen in globalen Aerosolüberwachungsnetzen sind auf Referenzgeräte (Artefakte) rückgeführt, die mit Hilfe von Langley-Verfahren in Messgeräteeinheiten kalibriert wurden. Kürzlich wurde eine SI-rückfgeführte Bestimmung der säulenintegrierten AOD demonstriert, die aus der passiven Fernerkundung der Atmosphäre mit SI-rückfgeführten Messungen der direkten solaren spektralen Bestrahlungsstärke gewonnen wurde. Dazu wurde ein Filterradiometer des Physikalisch-Meteorologischen Observatoriums Davos (PMOD), World Radiation Centre (WRC), das die direkte solare spektrale...

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New article in JOSA A:
Structured metasurfaces enable new possibilities for beam shaping and the miniaturisation of optical elements.
In the literature metasurfaces employing subwavelength structures are commonly related to anomalous reflection and refraction and associated with discontinuities of the wave vector at the interface.
In our article we employ classic diffraction theory to describe the far field diffraction pattern of such structured metasurfaces, define clear limitations for the applicability of generalized reflection and refraction laws and resolve some issues with misleading explanations.
The article supports the understanding of light propagation through subwavelength structured metasurfaces and contains important recommendations how to avoid misleading nomenclature.

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Auf der 123. Jahrestagung der Deutschen Gesellschaft für angewandte Optik (DGaO) in Pforzheim wurde Jan Krüger, Doktorand an der PTB, mit dem Posterpreis ausgezeichnet. Der Titel des Posters lautete: „Untersuchung des Schwingungseinflusses auf gemessene Punktspreizfunktionen in der optischen Mikroskopie“.

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Offers for Students

As is the case at PTB in general, in Division Optics there is the possibility to write a student thesis, to complete an internship or to participate in research as a working student. If you are interested in the topics and projects of the working group, you can first contact the Opens external link in new windowcentral contact persons and mention the working group as a request.
Offers for Doctoral Candidates

As at PTB in general, Division Optics is active in many collaborations (with link to new Div. collaboration page) with universities, research institutions, industry and other metrology institutes worldwide. These collaborations support many exciting third-party funding opportunities for PhD students to become involved in PTB research. If you are interested in the topics and projects of the working groups, you can first inquire at the Opens external link in new windowjob postings.