Non-Radiating Resonances: Anapoles Enabling Highly-Efficient Plasma Jets within Dielectric Structures

Plasma plays a pivotal role in numerous applications spanning the fields of medicine, industry, agriculture, and space exploration. When plasma interacts with air, it initiates unique chemical reactions, resulting in the creation of rare and highly sought-after reactive species. Typically, the generation of plasma jets for interaction with air relies on resonant cavities to enhance plasma efficiency. In this study, we have harnessed the innovative concept of non-radiating sources, known as anapoles, which utilize the lowest order multipoles specifically, electric-electric dipole interactions within a hybrid metallo-dielectric structure. This approach enhances the near electric field, facilitating gas breakdown for the realization of a plasma jet. The achievement of a dielectric plasma jet is remarkable in its own right, particularly when considering the open structure employed, which enables frequency tuning. Furthermore, the prototype we have demonstrated surpasses existing plasma jet technologies in several key aspects, including compactness, compatibility with planar fabrication techniques, power efficiency, cost-effectiveness, tunability, and a twofold increase in electron density compared to the highest levels achieved to date. With these substantial enhancements, our proposed device is poised to revolutionize the landscape of plasma source technology and open up exciting avenues for exploring novel applications.