VISUALIZATION OF NACRE STRUCTURE LAYERS BY SPECTRAL OPTICAL COHERENCE MICROSCOPY METHOD

The paper presents the study of surface layer structure of two nacre samples, plates of which served as mosaic elements in a subject of decorative art, by spectral optical coherent microscopy method at the wavelength range 1305 ± 75 nm with 10 μm scanning depth resolution. The mesolayers structure with thicknesses of 230 and 360 μm was observed within the B-scan of nacre layer for Haliotis shell. The tomogram of the second nacre sample is characterized by greater nonuniformity of layers' distribution through the scanning depth, strong scattering of probe radiation, and the microstructure of nacre is visualized in depth up to 1.6 mm. Comparison of the nacre sample layers structure by the optical coherence microscopy method provided for distinguishing their different biological origin. Analysis of the area for mosaic elements clamping to a base of the product is performed and the glue layer thickness is determined in the range from 67 microns to 120 microns.