High-precision wide-range gap measuring method and system based on spectrum phase

Abstract

The invention discloses a high-precision wide-range gap measuring method and a system based on a spectrum phase. The system can achieve space encoding of low coherence interference of sample light and reference light of different areas in an oversized range and interference signals of different areas, and the system can combine optical coherence tomography (OCT) technology, and achieve wide-range and high-precision gap measuring by adding of calibration units which are composed of Mach Zehnder interferometer (MZI). Due to the fact that a collection card synchronously takes samples of interference spectrum signals of two units, therefore, sweep frequency light source starting wave number and nolinear spectrum sampling in the two units are ensured to be consistent. The method based on the spectrum phase is utilized, calibration interference spectrum signals of each frequency sweeping period does not need to conduct equal-wave-number gap calibration, data processing time is shortened, and the effect of frequency sweeping light source shaking on the stability of the system can be greatly reduced. The method is simple, can achieve real-time processing, does not need to add extra complex devices and is easy to achieve.

Description

technical field [0001] The invention belongs to the field of optical coherence measurement, and in particular relates to a high-precision and large-range distance measurement method and system based on spectral phase. Background technique [0002] The distance between each lens in a modern optical system is a key indicator that determines the performance of the optical system and directly affects the imaging quality of the optical system. Therefore, people have proposed a method based on optical interference to measure the distance between lenses in an optical system, such as Time Domain Optical Coherence Tomography (TDOCT) adopted by the LenScan mirror locator of Fogale Company in France. The coherent light source and high-precision delay optical path obtain more accurate optical distance measurement results. However, the measurement speed and measurement accuracy of this system are limited by the speed and accuracy of mechanical movement in the high-precision delay optical...

AI Technical Summary

Problems solved by technology

Although the above methods can better improve the uncertainty of the initial wave number of the swept source, they all have inherent shortcomings and require the introduction of more complex devices

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