GRAPHICAL LENGTH MEASURING APPARATUS USING TWO-COLOR INTERFEROMETER

摘要

The present invention provides a length measuring apparatus using a two-wavelength interferometer, which economically and efficiently measures a length using an interferometer using a two-wavelength laser beam when a geometric length is measured; and maximizes an accuracy of the measurement by minimizing errors. The length measuring apparatus comprises: a light source part which irradiates an object with two laser beams having different wavelengths; a dividing part which divides the laser beam by reflecting a part of the laser beam, and allowing an other part of the laser beam to pass therethrough; a reflecting part; a measuring part; and a calculating part which measures a geometric length to the object.