بررسی نظری یک سنسور شاخص انکساری براساس اتصال هدایت بین فلدالهای فلزی فلز

We propose a refractive sensor based on directional coupling between two metal–insulator–metal (MIM) waveguides to detect the sample refractive index. It consists of a metal–insulator–metal–insulator–metal (MIMIM) waveguide in which surface plasmon waves (SPW) are excited. The directional coupling properties are analyzed by coupled-mode theory. The expressions about the coupling coefficient, coupling length and sensitivity are deduced. Simulation results show the total size of our sensor with MIMIM waveguide is about one tenth that of dielectric waveguide, and the sensitivity is improved to ten times.