| 摘要 |
An interferometer system for measuring a displacement along a first direction includes (1) a measurement roof optic (e.g., a porro prism) mounted to a stage translatable along the first direction, (2) a polarizing beam splitter having (a) a first face opposite the measurement roof optic and (b) a second face opposite the first face, (3) a first wave plate located between the measurement roof optic and the first face of the polarizing beam splitter, and (4) a redirecting optic located opposite the first face of the polarizing beam splitter. A measurement path through the system includes only segments located substantially in a plane defined by the first direction and a second direction orthogonal to the first direction. |
