In this experiment, the Raman spectra will be measured for several liquids, starting with carbon tetrachloride. Raman scattering is by its nature very weak. You must devise a method for getting the Raman scattered light into the spectrometer, while keeping out the direct laser light and any light which is scattered from other objects. The alignment is important here to make sure that the scattered light is going through the spectrometer. Note that there will always be a strong unshifted line at the frequency of the laser due to Rayleigh scattering.
Weaker lines require increased scan times.
Examine the dependence of spectra on incident wavelength and polarization. At times it may be necessary to open the cover of the spectrometer. The control for the shutter is located below the exit slit. This is the closed position. The open position is the other position where the knob clicks.