Depth calibrations of a 2D-CMOS-based partially coherent light interferometer

TL;DR

This paper presents a novel 3D surface topography measurement system using a 2D CMOS sensor with low coherence interferometry, enabling fast, non-contact depth measurements over areas without complex scanning.

Contribution

It introduces a new depth calibration method for a 2D-CMOS-based interferometer, enhancing rapid surface topography analysis without precise scanning.

Findings

Accurate depth calibration demonstrated for the system.

Potential for fast, non-contact surface topography measurement.

System achieves micrometric resolution over millimetric depth range.

Abstract

This work concerns the development of a 3D measuring system able to realize noncontact surface topography with millimetric depth-range and micrometric resolutions both in the spatial and depth axes. The optical concept is based on the well known low coherence interferometry (LCI) technique. The most widespread set-up of such technique is that of measuring only a point at a time with a 2D scanning system that permits the measure on an area. The novel concept of our instrument is based on the use of a 2D sensor (CMOS), where every single pixel measures a point on the object and this permits a fast analysis on square centimeters areas without the need for any precise (and expensive) scanning system. We present here accurate depth calibration which shows the potentiality of this instrument.