Micro-Raman spectroscopy: a powerful technique for materials research

Since the development of the holographic notch filters during the last deca de and novel detectors such as charge coupled devices, Raman spectroscopy i nstrumentation has evolved rapidly, so that modern spectrometers are orders of magnitude faster, present much lower signal to-noise ratio and simplifi ed optics than their predecessors. These advances have also had a significa nt effect in the construction of novel micro-Raman-dedicated spectrometers that currently use lasers with powers of the order of a few tens of mW. In the present work, a brief overview of current Raman spectroscopy technology in traditional spectrometers and of different applications of modern micro -Raman spectroscopy to the study of materials, ranging from epitaxial semic onductor thin films of interest to the optoelectronics industry, to biomate rials of interest to medical science, is presented. An emphasis is given to different acquisition modes that are possible when the excitation laser li ght is passed through a microscope objective and the sample is placed in a computer controlled XY stage. (C) 2000 Elsevier Science Ltd. All rights res erved.