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2026

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Ultrafast Holographic-Feel Optical Microscope

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A high-speed microscopy method for studying light–matter interactions makes it possible to observe optical processes on extremely short timescales. To this end, a German–Italian research team has innovatively combined holographic imaging with ultrafast spectroscopy. In this way, even transient electronic and magnetic phenomena—key players in the development and application of next-generation energy materials—can be directly observed.

This research was jointly conducted by scientists from the Institute of Physical Chemistry at Heidelberg University, the Polytechnic University of Milan, and the Institute of Photonics and Nanotechnologies in Milan. The findings have been published in the journal Nature Photonics.

At the heart of this study is a pump–probe microscope, which is used to perform so‑called pump–probe experiments. In these experiments, a short optical pulse first excites the material under investigation, while a second pulse subsequently records its time‑resolved response. By comparing measurements taken with the pump on and off, these processes can be reconstructed with high precision.

Dr. Julia Anthea Gessner explained: “By combining holographic imaging with ultrafast spectroscopy, we can observe and track electronic and magnetic dynamical processes with spatial resolution across timescales ranging from femtoseconds to picoseconds.” She is the project leader of Collaborative Research Center 1249, “N‑Heterocyclic Polycycles as Functional Materials,” and also heads a research group at the Institute of Physical Chemistry.

Dr. Martin Hörmann of the Polytechnic University of Milan explained: “The innovative method developed by the German–Italian research team enables simultaneous imaging of ultrafast electromagnetic phenomena across a wide field of view. Unlike other microscopy techniques, this approach makes it possible to image regions at the micrometer scale and to generate time-resolved movies of electron charge and spin dynamics.”

Furthermore, light‑induced changes in the optical properties of materials can also be visualized using this approach. “Our chiral optical method thus opens up new possibilities for directly observing dynamic processes in complex materials,” said Dr. Hörmann, who, together with Dr. Gessner and doctoral student Federico Visentin, played a key role in this study.

This high-resolution, ultrafast imaging technique is primarily designed for use in energy materials—materials that are integral to sustainable technologies such as solar cells, LEDs, spin‑LEDs, and innovative electronic components. Professor Felix Deschler of the Institute of Physical Chemistry at Heidelberg University emphasizes: “This microscopy method offers new insights into ultrafast optical processes, particularly regarding how these processes evolve with changes in a material’s composition and structure.”

According to Professor Franco V. A. Camargo, a scientist at the Milan Institute of Photonics and Nanotechnologies, research on the interaction between light and matter can provide crucial insights for the development of high‑efficiency, durable optoelectronic and spintronic devices.

Source: phys.org