Preliminary Study of Resonance Systems States in Surface Plasmon Resonance Systems

Abstract

Abstract Resonance between light and collective electrons is known as Surface Plasmon Resonance or SPR. The development of SPR-based sensors can generate the use of a Kretschmann configuration prism. Otto configuration dielectric medium between prism and gold thin film. For the Kretschmann configuration, a gold thin film between the prism and dielectric medium. So, this research focuses on the use of the Kretschmann configuration in the SPR system because the setup of the half-cylindrical prism is less complicated than using the Otto configuration. In this research, we compare the reflectance of an uncoated half-cylindrical prism and a half-cylindrical prism coated with a gold thin film to see the resonance effect. The beam reflected by the back surface of the prism was detected using a photodiode sensor (OPT-101, Texas Instruments). The photodiode sensor is connected to Arduino Uno, and the voltage reading results are processed with Arduino Ide software. Adjusting the He-Ne laser light’s angle of incidence and the prism’s angle of impact 30° – 50°. The experimental results show that the TIR (total internal reflection) phenomenon occurs in half-cylindrical prisms without a gold coating. Meanwhile, in the half-cylindrical prism coated with gold, a resonance phenomenon can be seen, this case, at a particular angle of incidence, can be detected through a reduction in the beam’s intensity of the reflected light. The photodiode sensor detects a decrease in voltage value, which indicates an intensity decrease, which was originally 4.34 volts to 2.52 volts when the incident angle of the light beam was 45°.