Six years after the first event, the scientific symposium marking World Interferometry Day on April 20, 2026, drew around 120 participants to Ilmenau, including representatives from research institutes, universities, and companies. Eight speakers from five countries and three continents highlighted just how diverse and dynamic the field of interferometry is today.
The Symposium
Since its first edition, World Interferometry Day has become a regular event in the international metrology community. The event is jointly organized by the Technical University of Ilmenau and SIOS Meßtechnik GmbH, with the clear goal of promoting scientific exchange on the fundamentals and applications of interferometry – across disciplines and institutions.
In 2026, the response was greater than in any previous year. The audience, drawn from academia, industry, and the university sector, asked challenging questions, discussed methodological details, and shared their own practical experiences. In addition to the presentations, a poster session provided an opportunity for direct exchange among researchers, industry representatives, students, and speakers.
Scientific Highlights
The wide range of topics covered in the program made it clear that interferometry today is much more than just a technology for length measurement. It spanned everything from the search for exomoons to spectroscopy using photons that never reach their detector.
Presentations were given by:
Prof. Guanhao Wu - Tsinghua University Peking
Dual comb interferometry: methodologies, systems and applicationsProf. Pascal Picart - LeMans Université France
How digital holography builds bridges for interdisciplinary researchDr. Chiara Lindner - Fraunhofer IPM Freiburg
Fourier-Transform Infrared Spectroscopy with Undetected PhotonsProf. Wolfgang Osten - ITO Stuttgart
The reconstruction, testing and improvement of the historical giant astronomical telescope in LilienthalProf. Jeff Kuhn - Institute for Astronomy, University of Hawaii
Interferometry and the search for extrasolar moons and life in the universeProf. Felipe Guzman - University of Arizona
Precision laser interferometry for inertial sensingPhD Marco Pisani – INRIM Italien
From meters to picometers: problems and solutions for practical interferometryDr. Gaoliang Dai - PTB Braunschweig
Novel hybrid interference and atomic force microscopy
“The program of presentations demonstrates the reputation this symposium has built,” said Dr. Denis Dontsov, Managing Director of SIOS Meßtechnik GmbH.
“The fact that scientists from China, France, the U.S., Italy, and Germany are coming to Ilmenau to discuss interferometry is not a given, but rather the result of six years of consistent effort. For SIOS, this international networking is of great value: We learn firsthand where research is headed and can assess which approaches will become relevant in applied measurement technology in a few years."
SIOS as a co-initiator and sponsorAs a co-initiator and sponsor of World Interferometry Day, SIOS was naturally in attendance. The development team attended the presentations to gain context for and evaluate current developments, as well as to assess which approaches might be relevant for SIOS users in the future. The goal was not to find ready-made answers, but to identify promising ideas at an early stage.
Visit to SIOS
Following the symposium, Dr. Denis Dontsov and Rudyard Urtecho hosted two of the international speakers – Prof. Guanhao Wu (Tsinghua University) and Dr. Gaoliang Dai (PTB Braunschweig) – for a tour of the company. The guests gained insights into the product portfolio and the current state of development. This is further proof that World Interferometry Day not only facilitates scientific exchange but also lays the groundwork for concrete dialogue.
Thanks to the Technical University of Ilmenau
A symposium of this caliber cannot be organized without a significant amount of effort. SIOS would like to thank the Technical University of Ilmenau for its many years of partnership and for its meticulous organization of the event.
See you next year
Over the past six years, World Interferometry Day has demonstrated that interest in interferometry – as a fundamental principle of precision measurement technology – is not waning but growing. The range of topics is broadening, the speakers are becoming more international, and the discussions are becoming more in-depth. Anyone interested in following developments in this field should mark their calendars for next year’s event.
We invite you to take a look at our photo gallery to experience the highlights of World Interferometry Day.
