Large-range contactless optical spacing measuring system and measuring method thereof

Abstract

The invention discloses a large-range contactless optical spacing measuring system and a measuring method thereof. The system comprises a light source, a first fiber coupler connected with the outputend of the light source, first and second circulators which are connected with two output ports of the first fiber coupler respectively, a reference arm connected with the second port of the first circulator, a sample arm connected with the second port of the second circulator, and a signal detecting and data collecting unit connected with the third port of the first circulator and the third portof the second circulator. According to the invention, high-precision spacing measurement in a wide range is realized through repeated interval ranging; the precision is only dependent on an SS-OCT system, and is not affected by the precision of the mechanical guide rail of the reference arm; the problem of the contradiction between the range and precision of the existing optical spacing measurement technology is solved; in the aspect of system construction, a multi-reflective surface structure has no strict precision requirements; SS-OCT main parts are composed of optical fiber connections; and the system has the advantages of convenient constructing and high reliability.

Description

technical field [0001] The invention relates to the field of optical measurement, in particular to a large-scale non-contact optical distance measurement system and a measurement method thereof. Background technique [0002] The structure of the current non-contact measurement device based on optical coherence tomography (OCT) is as follows: image 3 As shown, the light emitted by the laser enters the fiber coupler or beam splitter through port 1 and is divided into two paths, and enters the reference arm and the sample arm through ports 3 and 4 respectively; the light reflected from the sample arm plane mirror and each end surface of the sample to be tested passes through Return to the original path, and interference occurs; the interference information is converted into electrical signals by the photodetector through port 2, and finally collected and processed by the acquisition card and computer. [0003] OCT core components include lasers, Michelson interferometers and p...

AI Technical Summary

Problems solved by technology

However, most of the commonly used frequency-swept lasers are designed for biological tissue imaging, and limited by the sampling frequency of the data acquisition card, the imaging range of the frequency-swept OCT system is tens of millimeters

Therefore, it is still impossible to achieve distance measurement with optical accuracy of hundreds of millimeters

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