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1 July 1990 High-speed and high-resolution heterodyne interferometer
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Proceedings Volume 1319, Optics in Complex Systems; (1990)
Event: 15th International Optics in Complex Systems, 1990, Garmisch, Germany
In conventional heterodyne interferometer it Is necessary to provide a high-beat frequency laser when measurement for a high-speed target Is required1 . But use of the high-beat frequency laser makes the " nanometerdivisions" difficult. We have developed a novel interferometer system that has a sufficient response to high-speed movement of the target without Increase of the laser beat frequency. In this work a two frequency laser light passes through the same optical path of the interferometer so that two conjugate beat signals are obtained. By processing the multiple beat signals with a newly developed signal processor the above methodological contradiction is solved. l. OPTICS FOR LINEAR DISTANCE MEASUREMENT Optical system of the interferometer Is shown In Flg. l in which two frequency lights Fl and F2 (freq. f and f2) of orthogonally linear-polarized components of a two mode laser are used. A reference beat signal R (freq. r ) is generated from Fl and F2. Fl and F2 are passed through exactly the same path of the interferometer. A half power of Fl and F2 Is reflected and the rest Is transmitted In the beam splitter ( BS ). Polarization direction of the reflected beam is rotated for ir/2 after passing the X/4 plate twice. The transmitted beam Is reflected by a moving mirror (MM) mounted on the moving target so that frequency of the reflected beam Is shifted by Doppler
© (1990) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Shuko Yokoyama, I. Nishihara, A. Okamoto, Tsutomu Araki, and Norihito Suzuki "High-speed and high-resolution heterodyne interferometer", Proc. SPIE 1319, Optics in Complex Systems, (1 July 1990);

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