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 × 167 μm. 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 $\sqrt{320}$ or ≈ 18 times better signal-to-noise ratio.