Full-field high-speed optical coherence tomography system for evaluating multilayer and random tissues

Testing the condition of art subjects plays important role in reservation of Cultural Heritage. Optical Coherence Tomography (OCT) is a promising tool for nondestructive cross-sectional evaluating internal structure of material samples like varnish layer of paintings. It is important to use high-speed OCT systems for testing subsurface structure of objects with large area. In the paper, comparison of OCT systems from viewpoint of information capacity is given to select the most appropriate OCT system variant for evaluating 3D multilayer and random tissues. The method of sub- Nyquist sampling of OCT signals is considered that is used to decrease sampling speed in a few times. To provide high noise-immunity and stability when processing OCT signals with randomly variable parameters, the Kalman filtering method has been applied for evaluating sub-Nyquist sampled OCT signals. Experimental results of evaluating materials like varnish layer of paintings are presented and discussed.