Fiber-Interfaced Nanoprinted Hollow-Core Waveguide: A Novel Platform for Nanoparticle Tracking

The integration of functional components into flexible photonic environments is a key research area in integrated photonics, and particularly important for sensing applications, namely in nanoscience and bioanalytics, where minimizing sample volumes and reducing geometric device footprints are essential [1]. One aproach relies on using hollow core waveguides (HCWs) to enhance light-matter interaction, being particularly useful in the characterization of nano emsembles [2]. Within this framework, we demonstrate, for the first time, the use of a fiber-integrated nanoprinted HCW for the characterization of nanoparticles, using nanoparticle tracking analysis (NTA) as a key technique. Unlike previous approaches, that relied on performing NTA inside silica hollow-core fibers [2], [3], or using nanoprinted structures on chips [1], our method achieves seamless fiber-waveguide integration through precise 3D nanoprinting. This novel design eliminates the need for intermediate platforms, thus enhancing the system stability, accuracy, alignment-free, and nearly aberration-free imaging, thereby establishing a new benchmark on lab-on-fiber devices for high-precision NTA.