The time dependent varying shape of the laser beam within the scattering volume in Raman scattering experiments on LiNbO3 influences the recorded spectra and can be studied spectroscopically by forward-, right angle-, and backward-scattering geometries. The recorded spectra allow a time resolved insight into the microscopic local changes of the refractive index. The decay constant of the scattered phonon intensity is a well defined function of the laser power. It furthermore showed to be characteristic for the individual sample. Raman spectroscopy thus seems to provide a method to determine the concentration of Fe-impurities. We have observed that ordinary photons influence the optically damaged regions of the sample whereas undamaged regions are left almost unchanged. Damped cut-in oscillations recorded when illuminating the sample alternatingly with ordinary and extraordinary laser light seem to originate from local fluctuations of an excited cloud of impurity electrons. The observation of undamped periodic break downs of the scattering intensity from polaritons and back scattered phonons is reported.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.