A nanometeric temperature sensor based on plasmonic waveguide with an ethanol-sealed rectangular cavity

A surface plasmon polaritons (SPPs) temperature sensor which consists of two metal-insulator-metal (MIM) waveguides coupled to each other by an ethanol-sealed rectangular cavity is proposed. The transmission characteristics of the nanodevice are theoretically analyzed and numerically simulated by two-dimension finite difference time domain (FDTD) method. The temperature sensing characteristics of the SPPs waveguide sensor are systematically analyzed by investigating the transmission spectra. The results indicate that the position of the transmission peak wavelengths has a linear relationship with the ambient temperature. The temperature sensitivity increases with the increase of the cavity length and decrease of the cavity height. The temperature sensitivity of the nanometeric sensor can reach as high as −0.65 nm/°C. It could be utilized to develop ultracompact temperature sensor for high integration.