useful to build a Raman microscope with two different wavelengths as
close as 532nm and 632.8 nm (He-Ne)?
The raw spectrum below on a pyroxenite
section is a straightforward illustration of the advantage of this dual
laser configuration. The integration time of the 633 nm spectrum has
been reduced to avoid clipping of the signal. The Raman spectrum at 633
nm consists of small Raman peaks on a huge fluorescence signal. In the
532 nm spectrum, the fluorescence is moderate so that the signal
to noise ratio of the baseline corrected Raman spectrum is much higher.
Note that the two spectra have neither the same
wavelength scale nor the same peak positions. The spectrum wavelength
width is larger for the red laser and thus the resolution is better
although not visible in the figure below.