Ultra-large range space measuring system and method based on light cycle and spectral domain carrier frequency

Abstract

The invention discloses an ultra-large range space measuring system and an ultra-large range space measuring method based on light circulation and spectral domain carrier frequency. Gain compensation type light path mismatch circulating cavities are arranged in a sample arm and a reference arm of a swept-source optical coherent system, a series of equidistant reference light paths are formed on the basis of the light circulation of reference light and sample light in the light path mismatch circulating cavities, the low-coherence interference of the sample light and the reference light in different regions in the ultra-large range capability is realized, the space encoding of interference signals of different regions in the ultra-large range capability is realized on the basis of the multiplexing of a grating dispersion type carrier frequency device in an annular cavity, and the synchronous detection and decoding of the system are convenient. An interface positioning method of combining the wave number space phase with the peak point is adopted, the problems of axial resolution dependence and uncertainty of an extreme point positioning method are solved, in addition, the influence of chromatic dispersion mismatch on the positioning precision is eliminated, and the high-precision measurement of the ultra-large range space is realized.

Description

Technical field [0001] The invention belongs to the technical field of optical coherence measurement, and in particular relates to an ultra-long-range distance measurement system and method based on optical cycle and spectral domain carrier frequency. Background technique [0002] Modern optical systems are generally composed of multiple lenses. During the installation and debugging of the optical system, the spacing of the internal lenses is a key indicator that determines the performance of the optical system and is an important factor affecting the imaging quality of the optical system. There is a real-time large-range, high-precision distance measurement system to guide the installation and debugging of the above-mentioned optical system. [0003] In general industrial applications, mechanical measurement is generally used to measure the distance of each lens in the optical system. It is necessary to use a probe to directly contact the lens to be tested, which is easy to damage...

AI Technical Summary

Problems solved by technology

Although the above-mentioned image elimination method can suppress the image to a certain extent, it can only expand the range to twice the range when there is an image at most, and cannot break through the limited spectral resolution of the multi-channel spectrometer or the limited instantaneous linewidth of the sweeping light source. Limited measurement range

[0009] Second, the optical distance measurement accuracy of the FDOCT system is insufficient

Although these methods can effectively improve the spacing measurement accuracy of the FDOCT system, the maximum range is still limited by the range of the FDOCT system and cannot be used to measure samples with large axial scales.

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