Three dimensional microspectroscopic tomography with synchrotron radiation infrared raster scanning method

Abstract

A microspectroscopic tomography method is performed for a nondestructive three dimentional (3D) imaging. The synchrotron radiation infrared (SRIR) is used as a light source. A MiTeGen loop and a bird feather barb are taken as check samples. Their IR spectral informations are collected by raster scanning procedure with the incompleted projection mappings. Their 3D tomographic reconstructions are obtained by the penalized maximum likelihood algorithm with weighted linear and quadratic penalties (PML-Hybrid algorithm). The computed algorithm reconstructs the MiTeGen loop in the 1638–1572 cm−1 region, which corresponds to the NH bend vibration. Besides, the bird feather barb is measured in the mid-infrared spectral region, and the main characteristic absorption bands include amide A, the lipids, and amide I. Their 3D reconstruction images are obtained from three selected absorption bands. The results show that the 3D tomographic method presents a good signal-to-noise ratio (SNR). The 3D distributions of chemical compositions are obtained for the MiTeGen loop and the bird feather barb by SRIR microspectroscopic tomography.