TRANSMISSIVE ZONE PLATE, REFLECTIVE ZONE PLATE, SHAPE MEASURING METHOD, INTERFERENCE MEASURING DEVICE, AND MANUFACTURING METHOD FOR PROJECTION OPTICAL SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an interference measuring method for calibration without increasing unknown measurement error. SOLUTION: The interference measuring method uses a transmissive zone plate forming both a first wave surface being a null wave surface for a test plane and a second wave surface being a null wave surface for a Fizeau plane by using a pair of equivalent opposite sign graded transmission diffractive lights, in addition to use of an interferometer and a Fizeau lens for the test plane measurement. This zone plate enables to conduct interference measurement for calibration without increasing unknown measurement error, because it can form the two null wave surfaces (the null wave surface for the test plane and the null wave surface for the Fizeau plane).