METHOD FOR CONTINUOUS DETERMINATION OF OPTICAL LAYER COATING THICKNESS

摘要

PROBLEM TO BE SOLVED: To provide a method, which determines the optical layer thickness of coatings executed to both spherical surfaces of a concavo-convex lens, having different spherical radii and which can be executed comparatively simply. SOLUTION: During coating process, the concavo-convex lens is loaded with a light beam in a decentered manner. The reflection or the transmission of the light beam on a convex spherical surface and a concave spherical surface is measured with a photodiode. On the basis of the functional relationship between the reflection or the transmission of the light beam and the optical layer thickness, the optical layer thickness is found each time.