Magnetic field camera developed in cooperation project receives 1st prize at "Forum Junge Spitzenforschung"

As part of a collaboration between Fraunhofer-Heinrich-Hertz-Institut (HHI), Humboldt University of Berlin (HU) and the Ferdinand Braun Institute (FBH), a team of researchers has developed a new magnetic field camera. Julian Bopp, Felipe Perona and Tim Schröder (HU, FBH) designed the overall concept together with Hauke Conradi and Moritz Kleinert (Fraunhofer HHI). For his work on this project, Julian Bopp has now been awarded the first prize at "Forum Junge Spitzenforschung". The award is presented by the Industrial Research Foundation and the Berlin universities and is endowed with 10,000 euros for research funding.

Camera sensors for capturing weak magnetic fields - such as those caused by the transmission of stimuli through nerves - are used in non-invasive medical diagnostic procedures, for example. Until now, magnetic field cameras have been extremely complex and expensive devices. The magnetic field camera researched by Julian Bopp, on the other hand, is based on a new, significantly simplified measuring principle.

The basis of the so-called multi-pixel magnetometer is a newly developed optical quantum sensor with fiber optic coupling, which is based on nitrogen defects in diamond material. In the diamond chip, green pump and infrared laser beams intersect - each intersection point defines a camera pixel. Depending on the magnetic field applied, more or less infrared light is absorbed in the diamond, which can in turn be detected. To measure a magnetic field spatially resolved, the sample is simply placed on the diamond chip. The compact magnetic field camera with a spatial resolution of around 100 µm works at room temperature and can be integrated into portable devices. It was developed in a cross-institutional team and creates the conditions for compact, mobile magnetic field cameras. In addition to medical applications, the multi-pixel magnetometer may also be used to further develop batteries for the green mobility transition in the future.

The research work was coordinated in the Joint Lab Diamond Nanophotonics, which is operated jointly by HU Berlin and the FBH. Julian Bopp, Felipe Perona and Tim Schröder developed the overall concept with Hauke Conradi and Moritz Kleinert from the Photonic Components (PC) department at Fraunhofer HHI. The HHI researchers played a key role in the chip development and built the optical chip. This milestone was realized through the photonic integration of the sensor into the Fraunhofer HHI's PolyBoard platform. Fraunhofer HHI was also responsible for the coordinated design of additional components, such as the optical fibers.

Once a year, the Industrial Research Foundation and the Berlin universities hold the "Forum Junge Spitzenforschung" science competition to find young scientists with original and practice-oriented ideas and solutions that have emerged from their innovative fundamental research. This year's competition focused on sensors and data analysis.