FIVE-DEGREE-OF-FREEDOM HETERODYNE GRATING INTERFEROMETRY SYSTEM

摘要

A five-degree-of-freedom heterodyne grating interferometry system comprises: a single-frequency laser (1), used to emit single-frequency laser light, wherein the single-frequency laser light can be split into a reference light beam and a measurement light beam; an interferometer lens set (3) and a measurement grating (4), used to convert the reference light and the measurement light into a reference interference signal and a measurement interference signal; and multiple optical fiber bundles (5), respectively receiving the measurement interference signal and the reference interference signal, wherein each optical fiber bundle (5) has multiple multi-mode optical fibers respectively receiving interference signals at different positions on the same plane. The measurement system is not over-sensitive to the environment, is small and light, and is easy to arrange. Six-degree-of-freedom ultra-precision measurement can be achieved by arranging multiple five-degree-of-freedom interferometry systems and using redundant information, thereby meeting the needs of a lithography machine workpiece table for six-degree-of-freedom position and orientation measurement.