Affiliation:
1. Department of Physics and William Mong Institute of Nano Science and Technology The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong S.A.R. 999077 P. R. China
2. Department of Materials Science and Engineering City University of Hong Kong 83 Tat Chee Avenue Kowloon Tong Hong Kong S.A.R. 999077 P. R. China
3. Institute of Chemistry Far Eastern Branch of the Russian Academy of Sciences 159, prosp.100‐letiya Vladivostoka Vladivostok 690022 Russia
4. Institute of Automation and Control Processes Far Eastern Branch of the Russian Academy of Sciences 5, Radio St. Vladivostok 690041 Russia
Abstract
AbstractUncovering new ways for light localization at the micro‐ and nanoscale is essential for the development of state‐of‐the‐art photonic devices. Nowadays the most advances in this area are achieved using near‐field resonators, providing extreme light confinement in nanoscale volume. However, the boosting of device performance in some practical applications, for example, luminescent sensing, optical tweezing, and super‐resolution optical microscopy require light localization at distances beyond near‐field range. This issue can be addressed by employing dielectric microstructures that produce photonic nanojets (PNJs), representing an intermediate state between near‐field localization and geometric optics. Despite the promising benefits of PNJ implementation in various optical applications, their practical studies are scarce and mostly limited to numerical simulations. Here, a new type of PNJ is introduced and studied both numerically and experimentally. Contrary to the conventional case, wherein PNJ is generated by a single microstructure, the reported PNJ is produced through collective effects in a densely packed array of dielectric microstructures. The studies reveal that these collective PNJs can reach an unprecedented length of >60 λ, while maintaining a high localization intensity. Under certain configurations of the array, collective PNJ can enhance the electromagnetic field by up to sevenfold, being a versatile tool for various photonic applications.
Funder
William Mong Institute of Nano Science and Technology, Hong Kong University of Science and Technology