Linearity measurement of slit movement - uses laser interferometer with beam doubling and absolute beam separation measurement

摘要

The electrooptical linearity measurement device uses a laser, pref. a gas laser, and a mirror prism which reflects the laser beam. It is applicable to measurement of deviations of a slit intended to move along a straight line without the excessive expense associated with high accuracy measurements. The retroreflected laser measurement beam is directed into a beam doubling single axis inversion two-beam interferometer. A parallel displacement of the incident beam in a direction perpendicular to the interferometer axis and before the interferometer is measured absolutely as a relative distance between the partial beams after the interferometer.