Narrow nano-beam generation inside of silicon photonic chip with a hemi-cylinder

Abstract

Abstract A photonic nanojet (PNJ) can be shrunk using a high index dielectric micro-particle to generate a narrow nano-beam. Considering silicon has a high refractive index and low absorption in near-infrared waves, here, we present a narrow nano-beam generation inside of a silicon photonic chip with a hemi-cylinder. The proposed design consists of a silicon hemi-cylinder on a silicon substrate with a micro-hole. At first, we investigate the narrow PNJ inside of the silicon substrate produced by a silicon hemi-cylinder on a silicon substrate. In order to make the PNJ inside of the silicon substrate usable, the properties of the PNJ influenced by the position of the added micro-hole filled with water are studied. A narrow nano-beam can be obtained when the position of the added micro-hole is well-chosen. Then, the narrow nano-beam affected by the silicon hemi-cylinder immersed different mediums is presented. Finally, we discuss the influence of the perturbation of illumination angle on the properties of the nano-beam. The proposed structure may have potential applications in enhanced Raman spectroscopy and optofluidic chips.