Abstract
A micro-probe based on laser trapping is proposed for the micro-probe system of a nano-coordinate measuring machine. This study focused on the "shadow effect," which is the case wherein a partial beam for laser trapping is shaded by the specimen. A radially polarized beam was introduced to improve laser shading. As a result, the trapping efficiency was increased by 3.2 times. This high-efficient laser trapping made it possible for the proposed probe to measure the vertical surface under the shadow effect. The advantage of using radial polarization was confirmed via a measurement of the micro-groove profile.
