Overcoming the diffraction limit with high-index dielectric particles

Abstract

In this communication, we propose and demonstrate the ability to produce photonic nanojets using high refractive index dielectric particles immersed in air. An extremely narrow focus is produced just at the output surface of the proposed 2D and 3D particles with a spatial resolution of similar to 0.14 lambda(0) and similar to 0.06 lambda(0), respectively. In addition to the focusing performance, the imaging capabilities is also studied by introducing metallic spheres within the region of the photonic nanojet demonstrating that distances between objects as small as similar to 0.06 lambda(0) can be distinguished with the proposed structures.