| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable a heterodyne interferometer to generate highly parallel monochromatic rays which are properly separated. <P>SOLUTION: A beam source (110) for heterodyne interferometers generates rays containing components, having a circularly polarized light that has different frequencies and orthogonally crosses each other, and transmits the rays toward an isotropic single-mode optical fiber or a small number of optical fibers (130). The polarized of light emitted from the optical fiber (130) is converted into orthogonal linearly polarized light for use in the interferometers, and the frequency components are separated, according to linearly polarized light in the interferometers. Cosstalks between left polarization and right turn one in the optical fiber is small, thus completely separating the frequency components. A 1/4-wavelength plate (152) for converting the polarization of rays emitted from the optical fiber (130) or other optical elements has a table (156), having a tilt angle and roll angle adjustment function for adjustment to polarization, depending on bend in the optical fiber (130). The optical fiber (130) can have a highly rigid jacket or a short relaxation time to give stable output. <P>COPYRIGHT: (C)2004,JPO |
