Line focusing in micro-Raman spectroscopy.

In a microscope of a micro-Raman spectrometer a cylindrical lens is introduced to form a line-focus microprobe (LFMP). The dimensions of the LFMP are 0.66 x 167 microm. The lateral spatial resolution of Raman scattering with the LFMP is equal to the spatial resolution of the point-focus microprobe (PFMP). It is shown that the LFMP system enables measurements with a laser power density that is 320 times lower than the PFMP. For the same laser power density in both types of illumination, the LFMP Raman spectra give approximately radical320 or asymptotically equal to 18 times better signal-to-noise ratio.