High-precision Absolute Coordinate Measurement using Frequency Scanned Interferometry

TL;DR

This paper demonstrates high-precision 3D absolute position measurements using frequency scanned interferometry, achieving sub-micron accuracy in X and Y, and about 2 microns in Z, with potential for further improvements.

Contribution

It introduces a method for high-precision absolute coordinate measurement with FSI, extending previous distance measurement techniques to 3D positioning.

Findings

2D measurement precision better than 1 micron

3D measurement precision below 1 micron in X and Y

Z-axis precision around 2 microns

Abstract

In this paper, we report high-precision absolute position measurement performed with frequency scanned interferometry (FSI). We reported previously on measurement of absolute distance with FSI [1]. Absolute position is determined by several related absolute distances measured simultaneously. The achieved precision of 2-dimensional measurements is better than 1 micron, and in 3-dimensional measurements, the precision on X and Y is confirmed to be below 1 micron, while the confirmed precision on Z is about 2 microns, where the confirmation is limited by the lower precision of the moving stage in Z direction.