Foley & Lardner
Interferometer, adjusting method therefor, stage apparatus having the interferometer, and exposure apparatus having the stage apparatus
 This invention relates an interferometer having a structure for suppressing measurement errors arising from leakage light by minimizing nonlinear errors due to the leakage light in a polarization beam splitter for splitting incident light into a first polarized light component and a second polarized light component, and apparatuses to which the interferometer is applied. The interferometer includes an adjustment mechanism for adjusting the angle of light incidence on the beam splitting surface of the polarization beam splitter such that the extinction ratio of the polarization beam splitter is minimized by using the dependence of the polarization beam splitter on the incident angle. 
Nikon Corporation
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G01B G03F G01B G03F G01B
inventional inventional inventional inventional additional
Kinya Shigeru
Kato Takemoto