Study on the absorption characteristics and refractive index sensitivity characteristics of the periodic structure of double nanorods

Metamaterial perfect absorber is very important in the study of refractive index sensor. The time domain finite difference method used to simulate surface plasmon structure. double nanorod periodic structure designed, and parameters top layer are optimized according impedance matching principle, absorption rate light wave reaches 99.6% when wavelength about 12 mm. spectroscopy studied with change spatial medium around structure, sensitivity 4,008 nm/RIU, which can be measure gas.