Hybrid probing technique for coordinate measurement with optically trapped micro sphere

Engineered surfaces have been fabricated to provide enhanced properties such as low friction, anti-adhesive behavior, or low reflection of light. At micro-scales, surface force highly affects the functionality of mechanical parts. In order to reduce surface force such as friction, micro mechanical parts that have engineered surfaces are demanded. In order to investigate the functionality of the textured micro parts, it is necessary to evaluate both the three-dimensional shape and the surface topography along with its geometry. Then we propose novel hybrid probing technique using an optically trapped micro sphere. Tightly focused laser beam makes it possible for a dielectric micro sphere to sustain near the focal point in the air. The dynamic behavior of the micro sphere changes as the result of the interaction of the surface. Therefore, the surface is detected by monitoring the micro sphere. This enables the three-dimensional shape measurement of the substrate. On the other hand, Surface topography is imaged with the lensing effect of the trapped micro sphere. Therefore, this trapped sphere is used as both a probe for coordinate metrology and a micro-lens in optical microscopy in this study. This present investigation deals with the development and fundamental validation of the hybrid probing system with the optically trapped micro sphere. The measurement result with high performance was demonstrated using the tilted diffraction grating.