Novel Waveguide Surface Plasmon Resonance Sensor with Electrowetting Liquid Lens

Abstract

Surface plasmon resonance (SPR) has been widely utilized for immunoreaction measurements. In this study, a novel waveguide type surface plasmon resonance sensor with focal length variable liquid lens is described. The resonance angle and wavelength are determined with high sensitivity corresponding to the refractive index of the sensing material. The incident angle is varied by using an electrowetting liquid lens which is possible to actively change focal length by applying voltage. The angle of incident light is continuously changed from 73 to 78 degrees. The surface plasmon wave is excited between noble metal and a dielectric interface. The detection surface is prepared by coating silver metal on a high refractive index glass substrate. The incident light from a white light source passes through the substrate coated with a noble metal to detect the intensity of light according to varying incident angle. In this paper, the contribution of light with varying incident angle focuses on the angular properties of surface plasmon sensors with wide range of wavelengths is analyzed. This result suggests that the performance of the surface plasmon resonance sensor can be improved by changing incident angle.