Bidirectional confocal measurement of a microsphere

This paper presents the bidirectional confocal measurement of a microsphere, which enables the simple measurement of the sphere with a similar number of measuring points taken on its upper and its lower hemispheres. The innovative measuring strategy is the placement of the sphere above a mirror and the subsequent measurement of the upper hemisphere on the real sphere and the lower hemisphere on the mirrored sphere. While theoretical explanations are given first, the main focus of the paper is the presentation of the idea itself and the very promising empirical findings. We believe these findings prove that the measuring strategy presented has the potential to become a prime method for the optical characterization of microspheres.