OPTICAL PERFORMANCE MEASUREMENT APPARATUS OF TEST OPTICAL ELEMENT AND ITS CONTROL UNIT

摘要

A measuring apparatus measures an optical performance of a test optical element and includes a diffraction grating configured to emit diffracted light, an image sensor configured to capture an interference pattern formed by the diffracted light, and a controller configured to move the at least one of the diffraction grating and the image sensor in an optical axis direction, to capture a plurality of interference patterns before and after movements, and to calculate a light-condensing position based on a spatial frequency of a plurality of interference patterns and a moving amount.

主权项

1. A measuring apparatus configured to measure an optical performance of a test optical element, the measuring apparatus comprising:
an illumination optical system configured to emit light of a spherical wave; a diffraction grating configured to emit diffracted light based on the light from the illumination optical system; an image sensor configured to capture an interference pattern formed by the diffracted light; a moving unit configured to move at least one of the diffraction grating and the image sensor in an optical axis direction of the illumination optical system; and a controller configured to control the moving unit so as to move the at least one of the diffraction grating and the image sensor in the optical axis direction, to control the image sensor so as to capture a plurality of interference patterns before and after movements, and to calculate a light-condensing position of the illumination optical system based on a spatial frequency of a plurality of interference patterns and a moving amount of the at least one of the diffraction grating and the image sensor by the moving unit.