| 摘要 |
<p>An interference measurement using an interferometer and a Fizeau lens for measuring an object, wherein a calibration-use interference measurement can be conducted without increasing unknown measurement errors. A transmission zone plate forms a first wave front, a null wave front for an object surface to be measured and a null wave front for a Fizeau surface respectively by means of a pair of transmission diffraction light beams having an order of surface equivalent opposite signs. Although a single element, this transmission zone plate can form two null wave fronts (a null wave front for an object surface to be measured and a null wave front for a Fizeau surface). Therefore, this transmission zone plate, when used, enables a calibration-use interference measurement without increasing unknown measurement errors.</p> |
