The application of photoluminescence and Raman spectroscopy of synthetic diamond

The properties of the photoluminescent centres H3, 1.945 eV and their associated zero phonon lines (ZPLs) have been used to study various types of synthetic diamond in relation to their growth history. The shapes and widths of the 1.945 eV ZPL have been related to the presence of line and point defects in the different specimens using the theory of Stoneham and correlated with the crystal morphology. Micro-Raman spectroscopy has been used to study the spatial variation of internal stress in synthetic diamond, including single crystal and polycrystalline specimens. Micro-Raman mapping, in which the peak position and width of the allowed Raman peak in diamond are monitored, provides direct information on the state of stress and has been successfully employed to examine the stress distribution around cracks produced by indentation in the diamond.