# Measurement of dynamic interferometer baseline perturbations by means of wavelength-scanning interferometry

## TL;DR

This paper introduces a new wavelength-scanning interferometry method to measure rapid baseline perturbations in an interferometer's optical path difference, surpassing traditional spectral acquisition speed limitations.

## Contribution

It presents a novel demodulation technique and analytical model enabling high-frequency baseline variation measurement during spectral acquisition.

## Key findings

- Successfully captured fast baseline oscillations exceeding spectral rate.
- Validated the analytical model with experimental results.
- Demonstrated improved measurement capabilities over conventional methods.

## Abstract

A novel approach for measuring fast oscillations of an absolute value of interferometer optical path difference (OPD) has been developed. The principles of frequency-scanning interferometry are utilized for registration of the interferometer spectral function, from which the OPD is calculated. The proposed approach enables one to capture the absolute baseline variations at frequencies much higher than the spectral acquisition rate. Despite the conventional approaches, associating a single baseline indication to the registered spectrum, in the proposed method a specially developed demodulation procedure is applied to the spectrum. This provides an ability to capture the baseline variations which took place during the spectrum acquisition. An analytical model describing the limitations on the parameters of the possibly registered baseline variations are formulated. The experimental verification of the proposed approach and the developed model has been performed.

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Source: https://tomesphere.com/paper/1904.13134