In this study, a new ultra compact gas-sensor, based on a 2D photonic crystal waveguide incorporating with tapered microcavity, is designed to detect small refractive index changes. The refractive index (RI) sensor is formed by a point-defect resonant cavity in the sandwiched waveguide on Si slab with triangular lattice. The properties of the sensor are simulated by using the plane wave expansion (PWE) method and the finite-difference time-domain (FDTD) algorithm. The transmission spectra of the sensor with different ambient refractive indices ranging from n = 1.0 to n = 1.01 are calculated. The calculation results show that a change in ambient refractive index of Δn=1×10−4is apparent. The proposed sensor achieves a sensitivity (Δλ/Δn) of 523.2 nm/RIU. It was found that the resonance wavelength is a linear function of the refractive index in under study range. The sensor is appropriate for detecting homogeneous media.
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.
In this paper, a novel high-sensitive mid-infrared photonic crystal-based slotted-waveguide coupled-cavity sensor to behave as a refractive index sensing device is proposed at a mid-infrared wavelength of 3.9 µm. We determine the sensitivity of our sensor by detecting the shift in the resonance wavelength as a function of the refractive index variations in the region around the cavity. Comparison shows that mid-infrared photonic crystal-based slotted-waveguide coupled-cavity has higher sensitivity to refractive index changes than mid-infrared photonic crystal-based slotted-waveguide. The sensitivity can be improved from 938 nm/per refractive index unit (RIU) to 1161 nm/RIU within the range of n = 1-1.05 with an increment of 0.01 RIU in the wavelength range of 3.3651 µm to 4.1198 µm by creating a microcavity within the proposed structure, calculated quality factor (Q-factor) of 1.0821 × 10 7 giving a sensor figure of merit (FOM) up to 2.917×10 6 , and a low detection limit of 3.9×10 −6 RIU. Furthermore, an overall sensitivity is calculated to be around S = 1343.2 nm/RIU for the case of higher refractive indices of analytes within the range of n = 1-1.2 with an increment of 0.05 RIU. The described work and the achieved results by performing 2D-finite-difference time-domain (2D-FDTD) simulations confirm the ability to realize a commercially viable miniaturized and highly sensitive mid-infrared photonic crystalbased slotted-waveguide coupled-cavity sensor.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.