Optical grinder: sorting of trapped particles by orbital angular momentum

We customize a transversely structured, tunable light landscape on the basis of orbital angular momentum (OAM)-carrying beams for the purpose of advanced optical manipulation. Combining Laguerre-Gaussian (LG) modes with helical phase fronts of oppositeOAMhandedness, counter-rotating transfer of OAM is enabled in a concentric intensity structure, creating a dynamic grinding scenario on dielectric microparticles. We demonstrate the ability to trap and rotate silica spheres of various sizes and exploit the light fields' feature to spatially separate trapped objects by their size. We show the adaptability of the light field depending on the chosen LG mode indices, allowing on-demand tuning of the trapping potential and sorting criteria. The versatility of our approach for biomedical application is examined by spatial discriminating yeast cells and silica spheres of distinct diameter. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.

Automated summary

A transversely structured, tunable light landscape is customized based on orbital angular momentum (OAM)-carrying beams, allowing for advanced optical manipulation. By combining Laguerre-Gaussian (LG) modes with helical phase fronts of opposite OAM handedness, the transfer of OAM is demonstrated in a concentric intensity structure, enabling dynamic grinding on dielectric microparticles. The adaptability of the light field, depending on the chosen LG mode indices, is shown to allow for on-demand tuning of trapping potential and sorting criteria.