Around two million euros for research in laser technology at TU Braunschweig

Professor Stefanie Kroker has received a Consolidator Grant from the European Research Council (ERC) worth close to two million euros. With her working group at TU Braunschweig, Kroker is researching optical cavities, the component that makes laser systems the most precise instrument known to mankind. This key technology also enables regional collaborative projects such as the QuantumFrontiers Cluster of Excellence or the cluster4future Quantum Valley Lower Saxony (QVLS) to achieve the highest precision. The prestigious award also strengthens the research focus on metrology at TU Braunschweig and the Topical Group Novel Micro-Optomechanical Mirrors.

It takes finesse and steadiness for a laser to fulfil the high demands of quantum technologies. In laser development, the unit of finesse in combination with the stability of the mirrors determines how precisely the light beam delivers the desired wavelength. This finesse essentially depends on how well the mirrors in the centre of the laser, the optical resonator, reflect the desired light particles. At the same time, the same mirrors must remain as stable as possible in order to minimise disruptive noise.

Professor Stefanie Kroker and her team want to push the boundaries of what is possible with so-called meta-mirrors. These mirrors provide the necessary reflectivity in the smallest of spaces and integrate sensors, modulators and other optics into the mirror substrates. With the project name ‘MightyMirrors’, the idea has convinced the European Research Council (ERC), which supports Kroker with a Consolidator Grant of almost two million euros over five years.

Miniaturisation of quantum technologies

A look at the region shows just how much the powerful mirrors can drive research and technologies forward: complex systems such as the optical clocks of the QuantumFrontiers Cluster of Excellence or the quantum computer of the cluster4future Quantum Valley Lower Saxony require highly stable lasers with a wide range of wavelengths, in perspective even millions of times longer. Until now, however, not only has each wavelength required its own optical resonator, but also a lot of space on optical tables in specialised laboratories with low interference sources. The mirrors from the Institute of Semiconductor Technology at TU Braunschweig can make the decisive difference here.

‘With the ‘MightyMirrors’ project, we are tackling the integration of macroscopic, sensitive laboratory equipment on stable microchips. On the other hand, we want to generate several laser wavelengths in a single resonator using an entire grid of parallel meta-mirrors,’ says Professor Kroker. ‘Especially in cooperation with our project partners in the Braunschweig-Hanover region, we can see the multiple strengths of our meta-mirrors directly in action and continuously develop them further.’