Optical fiber distance measuring method and device

Abstract

The invention relates to a distance-measuring method and a device for an optical fiber, which comprises a wavelength-scanning light source (1), fiber-optical couplers (2, 2', 2''), fiber-optical gratings (3, 3'), a fiber-optical collimating device (4), a surface of an object for measuring (5), light-sensitive detectors ( 6, 6'), an A / D convertor (7) and a computer (8). Outlet light of the wavelength-scanning light source is separated to two paths through the fiber-optical couplers, one light path enters into the two fiber-optical gratings whose central wave length are different, reflected light of the fiber-optical gratings are detected by the light-sensitive detectors, the other path which enters into the fiber-optical collimating device is partially reflected by the end surface portion of the collimating device, the reflected light is partially reflected return to the fiber-optical collimating device by the surface of the object for measuring, two beams of the reflected light are detected by the light-sensitive detectors after being interfered. Output signal of the light-sensitive detectors is input into the computer through the A / D convertor, an distance between the end surface of the fiber-optical collimating device and the surface of an object for measuring is calculated through fourier transform white light interferometric phase demodulation method.

Description

technical field [0001] The invention belongs to the technical field of optical distance measurement, in particular to an optical fiber distance measurement method and a device thereof. Background technique [0002] High-precision absolute distance measurement is an important development direction of today's measurement technology. In order to improve the measurement accuracy and realize the non-contact absolute distance measurement, people have introduced optical interference technology; at the same time, in order to reduce the volume of the measuring instrument, simplify the structure of the optical path and improve the stability of the optical path, combined with the optical fiber sensing technology, the optical fiber interferometry is proposed. The method and apparatus (CN 1095536C, CN 1147702C) of distance. Optical fiber interferometric ranging can adopt the structure of Mach-Zehnder, Michelson or Fabry-Perot interferometer (actually Fizeau interferometer), in which the...

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Problems solved by technology

[0003] The purpose of the present invention is to solve the problems of low measurement accuracy, complex system and poor reliability of the existing optical fiber interference ranging method and its device, aiming to provide an optical fiber ranging method and its device with high measurement accuracy and simple structure

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