Highly sensitive refractive index sensor based on photonic crystal ring resonators nested in a Mach–Zehnder interferometer

Abstract

Today, with the rapid development of photonics, optical sensors are being considered as e cient tools for detecting environmental variations and have been regarded as one of the most important elds in photonic research. In this study, we have proposed a two-dimensional photonic crystal (2D-PC) refractive index sensor using a combination of Mach-Zehnder interferometers and two ring resonators. Our goal is to increase the sensitivity and gure of merit (FOM) of the sensor, so that the output transmission spectrum can be considerably shifted by changing the refractive index of the simulated analytes. The proposed photonic crystal sensor consists of a hexagonal array of silicon rods on a SiO 2 substrate. The nite difference time domain (FDTD) method is used for the numerical simulation of the structure. In this regard, to validate the simulation results, two different commercial software have been used. The qualityfactor (Q-factor) and the sensitivity of the proposed structure are more than 1600 and 1700 nm / RIU, respectively, where RIU stands for the refractive index unit. In general, the structure has advantages such as low fabrication cost, high sensitivity to changes in refractive index and a high Q-factor.

A Biomass Based Photonic Crystal Hydrogel Made of Bletilla striata Polysaccharide

“…These smart hydrogels can exhibit stimuli-responsive changes in their volume and structure, enabling various applications [ 24 ]. Optical sensing based on PhCs has several benefits such as low cost, accuracy, rapid response, and consistency of results [ 25 , 26 , 27 , 28 , 29 , 30 ]. As far as the PC-based biosensor sensitivity is concerned, many papers have mainly focused on the means of enhancing the sensitivity by many techniques [ 31 , 32 , 33 ].…”