An improved spectral optical coherence tomography technique is used to obtain cross-sectional ophthalmic images at an exposure time of 64 µs per A-scan. This method allows real-time images as well as static tomograms to be recorded in vivo.

A brief introduction to Optical Coherence Tomography (OCT) is presented, stressing the origin of the tomographic signal and the detection methods defining various modalities of the technique. The parameters of the tomographs, such as axial and lateral resolution, wavelength and intensity of the probing light, imaging range, time of examination, and sensitivity are then defined, and a paradigm for interpreting the OCT tomograms provided. The second part of the article comprises a review of the utilisation of OCT for structural examination of artworks, illustrated with some representative results. Applications to the structural imaging of semi-transparent subsurface layers such as varnishes and glazes, of underdrawings and of reverse painting on glass, are described first, and then applications in the examination of the structure and state of preservation of historic glass, jade, glazed porcelain and faience are discussed. Finally, the use of OCT combined with LIBS analysis and laser ablation of surface layers is presented.

The application of Fourier domain optical coherence tomography (FDOCT), a new implementation of incoherent light interferometry, to the examination of museum objects is described. The technique has been applied to the examination of porcelain and faience ceramics, and to the investigation of paintings. Time-resolved optical coherence tomography was used to study the surface profile of a painting during changes in the environment surrounding the object. The method provides precise section and surface profiles with micrometer resolution, and is complementary to other optical methods.

Purpose: Spectral optical coherence tomography (SOCT) is a new, noninvasive, noncontact, high-resolution technique that provides cross-sectional images of the objects that weakly absorb and scatter light. SOCT, because of very short acquisition time and high sensitivity, is capable of providing tomograms of substantially better quality than the conventional OCT. The aim of this paper is to show the application of the SOCT to cross-sectional imaging of the cornea and its pathologies. Methods: Eleven eyes with different corneal pathologies were examined with a slit lamp and the use of a prototype SOCT instrument constructed in the Institute of Physics, Nicolaus Copernicus University, Toruń, Poland. Results: Our SOCT system provides high-resolution (4 μm axial, 10 μm transversal) tomograms composed of 3000-5000 A-scans with an acquisition time of 120-200 ms. The quality of the images is adequate for detailed cross-sectional evaluation of various corneal pathologies. Objective assessment of the localization, size, shape, and light-scattering properties of the changed tissue is possible. Corneal and epithelial thickness and the depth and width of lesions can be estimated. Conclusion: SOCT technique allows acquiring clinically valuable cross-sectional optical biopsy of the cornea and its pathologies.