Comparison between optical coherence tomography and phase shifting profilometry for surface estimation

Abstract

Profilometry is the technique that estimates the surface height and tomography of a sample. This technique is crucial to correct the intensity variations and angle changes when optical properties of a sample are estimated and its calculation depends on the surface profile. Two systems have been evaluated in this work: an Optical Coherence Tomography (OCT) system and a Spatial-Frecuency Domain Imaging (Hyperspectral-SFDI) system made up of a rotating mirror hyperspectral camera and a Red-Green-Blue (RGB) projector. The estimation of the height map with the OCT system based on the high contrasted backscattering of the air-sample interface whereas, while with the HSI-SFDI system the Phase Shifting Profilometry (PSP) technique has been implemented employing different frequencies. This work compares both approaches and evaluates the differences between them.