Design of a hybrid photonic-plasmonic crystal refractive index sensor for highly sensitive and high-resolution sensing applications

Abstract

In this paper, an optical refractive index sensor based on a hybrid photonic-plasmonic crystal (PhPlC) topology, in which some metal nano-rods are embedded in a rod-type GaAs photonic crystal (PhC) lattice, is proposed. The FDTD method is used for numerical simulation of the sensor. The simulation results illustrate a fairly high sensitivity of 1350 nm/RIU, a high figure of merit (FoM) of 488 RIU−1, and a detection of limit of 2.04×10−4 RIU. The sensitivity of the PhC sensor is dramatically enhanced by employing the excitations of plasmonic mods of the metal nano-rods in the sensor structure. The sensitivity and FoM of the proposed sensor are significantly improved compared to the results published in the literature. The higher sensitivity and the larger FoM are the two important features of the proposed sensor which make it an incredibly suitable candidate for sensing applications in optic communication wavelengths.