The Influence of the Structural Parameters of the Materials of the Sensitive Element of the Optical Sensor on Its Sensory Properties

Abstract

The sensor element of an optical sensor based on surface plasmon resonance is investigated in the paper. In particular, the influence of the components of the sensor element on its sensor properties by modeling design options. The Kretschmann configuration was chosen as the model, which is a glass prism with a multilayer nanoscale structure applied to one face. It was established that the material of the prism affects only the resonance angle of the structure. The thickness of nanoscale gold and silver films varied from 1 to 100 nm. The minimum value of the coefficient was obtained when the thickness of the gold and silver nanoscale films was 50 nm and 45 nm, respectively. The thickness of the silicon dioxide film varied from 10 to 150 nm. In the Au – SiO2 structure, the addition of silicon dioxide improved the optical properties of the multilayer structure. The minimum value of the reflection coefficient has decreased, but the thickness of the silicon dioxide is 3 nm. When the thickness of the dielectric layer increases, the optical properties of the structure deteriorate. The structure of the sensitive element, which uses a nanosized silver film, almost does not change its optical properties when adding a layer of SiO2, its thickness can reach 50 nm.