From material selecting, cutting, curvature generation, polishing, to coating, every treatment in the process of optical component producing will affect the accuracy and the quality of the optical products.
On polishing, it is easy to cause cracks on the surface of the optical components. Visual inspection is the main measure to examine the defects on the surface. The accuracy of visual inspection relates to the inspectors’ professional experience. The accuracy also relates to inspection equipments. However, it is difficult to take pictures of the curved optical components and to reduce the reflection from those components.