| 摘要 |
PURPOSE: To provide a polarization interferometer which can improve the contrast of interference fringes without loosing the whole quantity of light. CONSTITUTION: The light from a laser light source 11 which outputs linearly polarized light is split into two linearly polarized light fluxes which are polarized in two directions intersecting each other at right angles through a polarization beam splitter PBS after passing through a halfwave plate HWP inserted immediately after the light source 11 and a lens system 12. The split linearly polarized light fluxes are again synthesized into one luminous flux through the beam splitter PBS after one flux irradiates a reference surface 15 as reference light and the other flux irradiates a surface to be measured (sample) 14 as sample light. When the two polarized light fluxes are synthesized, the fluxes are respectively transformed into clockwise and counterclockwise circularly polarized light fluxes through a l/4-wave plate QWP3 provided at angles 45 deg. from the x-axis and y-axis.
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