집적광학 바이오케미컬 센서에 적합한 Si3N4/SiO2 슬롯 및 릿지-슬롯 광 도파로 제원 최적화 및 감지도 해석

Abstract

Numerical analysis was performed using FIMMWAVE to optimize the specifications of Si3N4/SiO2 slot and ridge-slot optical waveguides based on confinement factor and effective mode area. The optimized specifications were confirmed based on sensitivity in terms of the refractive index of the analyte. The specifications of the slot optical waveguide, i.e., the width of the slot and the width and height of the rails, were optimized to 0.2 µm, 0.46 µm, and 0.5 µm, respectively. When the wavelength was 1.55 µm and the refractive index of the slot was 1.3, the confinement factor and effective mode area of 0.2024 and 2.04µm2 , respectively, were obtained based on the optimized specifications. The thickness of the ridge and the refractive index of the slot were set to 0.04 µm and 1.1, respectively, to optimize the ridge-slot optical waveguide, and the confinement factor and effective mode area were calculated as 0.1393 and 2.90 µm2 , respectively. When the confinement coefficient and detection degree of the two structures were compared in the range of 1 to 1.3 of the analyte index, it was observed that the confinement coefficient and sensitivity were higher in the ridge-slot optical waveguide in the region with a refractive index less than 1.133, but the reverse situation occurred in the other region. Therefore, in the implementation of the integrated optical biochemical sensor, it is possible to propose a selection criterion for the two parameters depending on the value of the refractive index of the analyte.