Mid-infrared Refractive Index Sensor Based on a 2D Photonic Crystal Coupled Cavity-two Waveguides

Abstract

In this paper, a viable design of mid-infrared refractive index sensor based on photonic crystal coupled cavity-two waveguides is proposed. An increasing number of works are dedicated to investigate the behavior of refractive index sensor based on photonic crystal in the mid-infrared range. We define the sensitivity of our sensor by detecting the shift in the resonance wavelength as a function of the refractive index's variations in the region around the cavity. The purpose of this study is to design a highly sensitive mid-infrared photonic crystal sensor. Consequently, an improved sensitivity of 650 nm/RIU (refractive index units) with a detection limit of 0.001 RIU has been obtained. The sensitivity can be improved from 394 nm/RIU to 758 nm/RIU with a detection limit of 0.01 RIU in the wavelength range of 2,97 µm to 3,71 µm by increasing the number of the infiltrated holes. The same design has been used as a liquid sensor and a sensitivity of 550 nm/RIU has been achieved with a detection limit of 0.001 RIU for RI=1.33 and RI=1.331. The properties of the sensor are simulated using the finitedifference time-domain (FDTD) method from the RSoft software package.

High-Performance Two-Dimensional Photonic Crystal Biosensor to Diagnose Malaria Infected RBCs

“…For the propagation of light inside the structure, the center free space wavelength used is 1550 nm as this wavelength is suitable and well-known for biosensing purposes. To break the periodicity of the structure and localize the light, two photonic crystal waveguides W1 are created by removing one row of air holes in the ГK direction, and a ring-shaped defect was introduced into the center of the structure by removing seven lattice holes, to form one ring-shaped cavity, and by separating the ring-shaped cavity and the two waveguides by three holes to generate localized optical modes that resonate in this ring [14] (Fig. 2).…”

High-Sensitive Mid-Infrared Photonic Crystal Sensor Using Slotted-Waveguide Coupled-Cavity

“…A T-slotted photonic crystal sensor was designed and proposed by Turduev et al [37], and the sensitivity of 500 nm/RIU has been achieved. A mid-IR refractive index sensor based on 2D photonic crystal coupled cavity-two waveguides was also investigated in [38], and the sensitivity of 758 nm/RIU for a refractive index range of n = 1.01-1.04 and sensitivity of 500 nm/RIU for a refractive index range of n = 1.33-1.331 have been attained. In this work, we propose a novel high-sensitive mid-IR photonic crystal sensor with beyond 1000 nm/RIU sensitivity and Q-factor of more than 10 7 .…”