Method and apparatus for transmission measurement of the geometrical structure of an optical component

Abstract

The invention provides an apparatus and a method for measuring the geometrical structure of an optical component (2) in transmission, comprising the steps: of illuminating the optical component by means of a first incident beam (8, 10), the wavefront of which is known, of measuring by deflectometry (16, 18) the wavefront of said first beam after transmission by said optical component, of illuminating the optical component by a second incident beam (12, 14), the wavefront of which is known, of measuring by deflectometry (16, 18) the wavefront of said second beam after transmission by said optical component, and of calculating the geometrical structure of said optical component from the wavefronts measured during said measurement steps. The measurement of the light transmitted in two distinct optical configurations allows a calculation by optimizing the two surfaces of the component, without prior knowledge of one of the surfaces. The first and second beams may be different and may illuminate the same surface of the component; thus it is possible to use identical beams and to illuminate each surface of the component in succession.

Dependencies are inferred from the claim text.