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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 Abteilungsbericht aus dem Jahresbericht 2020

Der Initiates file downloadAbteilungsbericht gibt einen Überblick über die wichtigsten Nachrichten und Ereignisse der Abteilung „Optik“ des letzten Jahres und ergänzt somit den Opens internal link in current windowJahresbericht-2020 der PTB.


In quantum communication systems, the precise estimation of the detector´s response to the incoming light is necessary to avoid security breaches. The typical working regime uses a free-running single-photon avalanche diode in combination with attenuated laser pulses at telecom wavelength for encoding information. We demonstrate the validity of an analytical model for this regime which considers the effects of dark counts and dead time on the measured count rate. For the purpose of gaining a better understanding of these effects, the photon detections were separated from the dark counts via a software-induced gating mechanism. The model was verified by experimental data for mean photon numbers covering three orders of magnitude as well as for laser repetition frequencies below and above the inverse dead time. Consequently, our model would be of interest for predicting the detector response not only in the field of quantum...

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The Max-Planck-RIKEN-PTB Center for Time, Constants, and Fundamental Symmetries holds a workshop on recent advances on Tuesday March 9th, 2021, with the following speakers:

Ichiro Ushijima (RIKEN): Transportable optical lattice clocks with 18 digit precision
Richard Lange (PTB): Improved Limits for Violations of Local Position Invariance and Local Lorentz Invariance from Atomic Clocks
Peter Micke (PTB): Coherent laser spectroscopy of highly charged ions using quantum logic
Matthew Anders Bohman (MPIK/RIKEN): Sympathetic Cooling of Trapped Protons
Antonia Schneider (MPIK): High-precision measurement of the hyperfine structure of 3He+ in a Penningtrap
Kathrin Kromer (MPIK): Latest results of the high-precision mass measurements with PENTATRAP
Jack Devlin (CERN/RIKEN): Constraining the coupling between axion-like dark matter and photons using an antiproton superconducting detection circuit in a cryogenic Penning trap

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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.