Generation, Adjustment and Potential Application of Photonic Nanojets

The photonic nanojet (PNJ) was discovered twenty years ago and has attracted much attention due to its sub-diffraction-limited beam width and high intensity. Unlike plasmonic hotspots, PNJs do not require metal components or complex alignment methods. Their generation depends critically on refractive index differences, particle size, shape, and illumination conditions. Active tuning mechanisms include changing wavelength, polarization, or wavefront, mechanical deformation, thermal or acousto-optic effects, and integration with microfluidic platforms. These capabilities enable a variety of applications, including super-resolution imaging, nanopatterning, laser machining as a “light pen” for manufacturing at 100 nanometers and below, optical trapping of nanoparticles, and ultrasensitive plasmonic and Raman sensing.This Research Topic explores the open issues and challenges in the generation, adjustment, and potential application development of PNJs. Key challenges include: how to use simple, cost-effective dielectric structures — including various particle shapes and core-shell architectures — to generate PNJs with controllable beam width, intensity, and working distance; how to actively and dynamically adjust the position, focal length, bending angle, or array of PNJs without mechanical scanning; and how to integrate PNJ generators into practical systems such as super-resolution microscopes, nano-patterning tools, and lab-on-chip devices. Other unresolved issues include material limitations, throughput of parallel operations, and long-term stability.We welcome contributions addressing these fundamental and engineering challenges across imaging, sensing, manufacturing, and bio-photonics. We particularly encourage submissions featuring experimental validation and quantitative benchmarking of PNJ performance, alongside theoretical and simulation-based studies Topic editors: Song Zhou, Samir Mondal Source: https://www.frontiersin.org/research-topics/84792/generation-adjustment-and-potential-application-of-photonic-nanojets