Implementation of an Optical Coherence Tomography System for Painting Characterization

Abstract

Optical Coherence Tomography (OCT) is a new but well established imaging technique for medical diagnosis, which can produce two- or three-dimensional images of bio-tissues with a few µm spatial resolution. Its potential as a non-invasive tool for art conservation of paintings and other objects has been realized recently. In this work, we report the implementation of two OCT systems applied to painting characterization. One system operates in the so-called spectral domain, with a central wavelength of 840 nm and axial resolution of 10µm. The second system has its central wavelength at 1280 nm, with spatial resolution of 20µm, and operates in the time domain. Both systems are independently controlled and have imaging software developed in-house using LabView. Using both systems, a 15 years old acrylic portrait has been analyzed, where the paint layers, light and dark colors, and the cotton threads of the canvas could be identified.