High Q-factor resonance in a symmetric array of all-dielectric bars

Abstract

Strong electrical dipole resonance (ER) with high quality-factor (Q) (over several thousands) in a simple silicon all-dielectric rod arrays without asymmetric structure is achieved in the near infrared (NIR) wavelength range. According to numerical simulations, strong high order ER is excited by vertical incident plane waves with electric fields polarized perpendicular to the rod instead of parallel. The electric field coupling between adjacent rods is greatly enhanced by increasing the length of the rods, and the radiative loss of the ER is significantly depressed, thus achieving high Q resonances. In the meantime, the electric field enhancement both inside and surrounding the rod are greatly improved, which is conducive to many applications. The proposed all-dielectric metasurface is simple, low loss, Complementary Metal Oxide Semiconductor (CMOS) compatible, and can be applied in many fields, such as sensing, narrowband filters, optical modulations, and nonlinear interactions.