Theoretical and experimental study of a 30 nm metallic slot array

Abstract

We present the simulation, fabrication, and characterization of a metallic slot grating on a silicon waveguide (30 nm slot width for a period of 500 nm). According to the simulation, the experimental measured spectrum of the structure exhibits a dip in the near-infrared region. Moreover, the finite-difference time-domain simulation shows that this device can be used as a sensor, due to its high sensitivity to the refractive index variation of the medium above and inside the cavity (η=Δλ/Δn=750 nm/refractive index unit).