| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a positioning device capable of removing Abbe aberrations. <P>SOLUTION: In the positioning device that includes a laser interferometer loaded on a slider, and a fixed mirror, the slider is positioned by measuring the length, based on laser interference, by using laser light making a round trip between the laser interferometer and the fixed mirror. The positioning device also includes a mirror for varying an optical path of the laser light, by bending the linearly polarized laser light acquired from the laser interferometer, and a quarter-wave plate for varying the laser light via the mirror into a circularly polarized laser light and irradiating the fixed mirror therewith. <P>COPYRIGHT: (C)2011,JPO&INPIT |
