抄録
Three-dimensional metrology is demanded to inspect the manufacturing performance of miniaturized products with nano/micro scale. To satisfy the specific requirements for coordinate metrology, we have developed an optically trapped probe, whose principle is based on single beam trap of a microsphere in air. In this paper, as a scanning measurement method of a micro free form surface, the novel nano-profile measurement technique by scanning an optically trapped probe is proposed, which is used as a sensor to read a standing wave scale (SWS) based on the interpolation method. An axial position of the microprobe sphere was measured using a chromatic confocal system to interpolate the SWS with high accuracy and high resolution. The length and the resolution of the interpolated SWS could be achieved 3 μm and 20 nm, respectively. In order to verify the validity of the proposed scanning measurement technique, the surface profile measurement of a glass small lens with accuracy higher than 50 nm was demonstrated.
