Is used for the form measuring method and its manner of the transmitted wave front of suffering measurement ones the device

摘要

PURPOSE:To measure the shape of a transmission wavefront of a substance to be measured, by using interference patterns formed of reflection wavefronts from first and second reflecting surfaces, and the lateral surface of the substance to be measured, etc. CONSTITUTION:Based on an interference pattern formed of a reflection wavefront of a light emitted from an interferometer (not shown) and reflected on first and second reflecting surfaces 1 and 3, an optical path distribution obtained from the shape of the wavefront in a state wherein a substance 6 to be measured is absent in optical paths, is determined. Next, the optical path distribution containing a change in the shape of the reflection wavefront of the reflecting surfaces 1 and 3 in a state wherein the substance 6 to be measured comes into the optical paths, is determined. Moreover, based on an interference pattern formed by the reflecting surface 1 and one side surface 6a of the substance 6 to be measured, the optical path distribution containing the change in the shape of the reflection wavefront caused by the side surface 6a of the substance 6 to be measured is determined. Based on an interference pattern formed by the reflecting surface 3 and the other side surface 6b of the substance 6 to be measured, subsequently, the optical path distribution containing the change in the shape of the reflection wavefront caused by the side surface 6b of the substance 6 to be measured is determined. From these optical path distributions, the shape of a transmission wavefront of the light transmitted through the substance 6 to be measured can be measured accurately.