| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser length-measuring apparatus, capable of precisely obtaining the difference of distance between an object to be measured and a laser beam input/output plane (measurement baseline position) of an optical fiber directed to the object to be measured, regardless of the changes in the optical path length of the optical fiber. SOLUTION: The apparatus comprises a self-coupled laser element which irradiates the object to be measured with a wavelength-modulated laser beam via optical fiber, and into which a laser beam, reflected by the object to be measured, is introduced via optical fiber; a light-receiving device for receiving the wavelength-modulated laser beam output from the laser element; and a signal processing means which applies frequency analysis to the modulated laser beam, received by the light receiving device and obtains the difference in the distance between the object to be measured and the laser beam input/output plane, based on a frequency component of light caused by the interference of the reflection light from the object to be measured and the reflected light from the laser beam input/output plane (measurement baseline position) of the optical fiber. COPYRIGHT: (C)2007,JPO&INPIT
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