Development of a sensing device for detecting refractive index changes by using a plasmonic resonator

The authors present a sensing device for detecting refractive index changes by using a plasmonic resonator. The detection performance of the device has been numerically evaluated by the finite-difference time-domain method. The device can detect refractive index changes of 10 to the negative sixth power if a light with the wavelength of 633 nm is used as excitation source, theoretically. We have fabricated the plasmonic square resonator and evaluated it.