Surface plasmon resonance microscopy for optical EHL measurement systems

This study investigates the suitability and limitations of surface plasmon resonance (SPR) microscopy for optical elastohydrodynamic lubrication (EHL) measurement systems. SPR microscopy developed in this study can quantify the lubricant density distribution in contact region with high spatial-temporal resolution using simple total reflection optical systems. It means that, if either the temperature or pressure distribution can be estimated, the other can be calculated. To examine the practicalities, we determined specific optical setting conditions such as the incident angle and thickness of each film layer for surface plasmon excitations under EHL conditions based on numerical calculations and demonstration experiments.