Discussion on Surface Plasmon Resonance Technique in the Otto Configuration for Measurement of Lubricant Film Thickness

摘要

This study presents a novel method of in situ observation of lubricant films formed within contact interfaces, focusing on the use of the surface plasmon resonance (SPR) technique in the Otto configuration, i.e., the SPR-Otto system. First, a numerical analysis based on the multiple-beam interference theory showed that the SPR-Otto method proposed in this study exhibits high sensitivity for the measurement of lubricant film thickness, comparable to that of a well-known optical interferometry method. Additionally, the advantages and disadvantages of the SPR-Otto method were considered on the basis of the numerical results. Subsequently, a model experiment was performed using an SPR-Otto optical microscope newly developed in this study to demonstrate the predictions obtained in the numerical analysis.