Device and method for eliminating signal jitter measured by white light interferometer

Abstract

The invention discloses a device and method for eliminating signal jitter measured by a white light interferometer. The method comprises steps: the wide-spectrum light emitted by the white light interferometer is divided into two paths and enters a measurement arm and a reference arm respectively; the reference light in the reference arm and the measurement arm Beat-frequency interference occurs in the signal light in the signal to generate the first beat-frequency signal; the narrow-linewidth high-coherence light is divided into two paths, one path passes through the reference arm, and the other path is generated by the narrow-linewidth high-coherence light output by the reference arm Beat frequency interference to generate a second beat frequency signal; use the processed second beat frequency signal as an external clock trigger signal to collect the processed first beat frequency signal; process the collected data and convert it into an event point to be measured power-position curve. The invention can eliminate the signal jitter produced by the inherent characteristics of the optical delay line in the measurement signal of the white light interferometer.

Description

technical field [0001] The invention relates to the field of optical measurement, in particular to a device and method for eliminating signal jitter measured by a white light interferometer. Background technique [0002] White light interferometer is an effective means and solution for measuring weak optical signals. Using the extremely short coherence length of white light, the detection and location of extremely weak signals can be realized. The white light interferometer usually uses an optical delay line to scan a certain distance, and observes the interference peak of the beat frequency spectrum to judge whether there is an event point, the position of the event point, and the echo power of the event point. [0003] However, due to the inherent characteristics of the optical delay line itself, its scanning speed cannot be maintained at a constant speed. If a fixed sampling rate is always used, then the distance scanned in the same period must be longer or shorter, whic...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to propose a device and method for eliminating the signal jitter measured by the white light interferometer in view of the non-uniform scanning speed of the optical delay line in the current white light interferometer and the beat frequency jitter caused by the optical path jitter caused by mechanical friction.

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