From Concept to Chip Researchers at Leibniz IPHT and Ludwig Maximilian University of Munich Have Created Microscopic Light- Guiding Structures

For the first time, researchers from Jena and Munich have fabricated a twisted hollow-core waveguide directly on a chip. This “twisted light cage” enables light to be guided along controlled spiral paths and allows different rotational states of light to be distinguished. This approach opens new possibilities for analyzing and manipulating materials and molecules that respond to the handedness of light.

In conventional waveguides, light propagates in straight lines. In the new structure, however, light follows a twisted path, with up to one full rotation over less than a tenth of a millimeter. “This allows us to achieve twist strengths that exceed those of previous hollow-core systems by orders of magnitude,” says Prof. Markus Schmidt, head of the Fiber Photonics research department at Leibniz IPHT.

This controlled twisting generates chiroptical effects: light with different handedness is guided differently. The degree of twist can be precisely adjusted, enabling experimental studies of chirality-dependent light– matter interactions. At the same time, the hollow core remains accessible. Gases or liquids can be introduced to investigate optical interactions within the structure under controlled conditions. Prof. Markus Schmidt developed the concept and design of this twisted structure together with Johannes Bürger, Thomas Weiß, and Prof. Stefan A. Maier from Ludwig Maximilian University of Munich. Fabrication was carried out at Leibniz IPHT using 3D nanoprinting, while optical characterization and theoretical analysis were performed in Munich.

These twisted light structures could be used in the future for sensing, quantum photonics, and lab-on-achip technologies. Since the hollow core is accessible to gases and liquids, it is possible to study chemical and biological processes optically within the structure.

Original Publication: https://doi.org/10.1117/1.AP.7.4.046002