Raman spectroscopy uses a laser excitation source to induce scattering from the targeted sample. The spectrometer is used to detect this low-level return signal to identify the sample makeup. The popularity of Raman is growing over the competitive IR analysis technique because no sample preparation is required and silica fiber optics and detectors are efficient and low cost in the VIS and NIR wavelength regions. There are several popular laser excitation wavelengths such as 532, 632, 670, and 785nm. The standard StellarNet Raman spectrometer is configured for a 785nm laser with optics to handle measurements in the NIR range from 785-1150nm. If another range is desired, specify the laser wavelength after the R in the spectrometer model number. This provides a Raman shift range of 200-4000cm-1 wave numbers to the right of the laser line (Stokes). A slit is installed to set the optical resolution and should match the laser line width. A 50um slit provides 2.4nm (~40 cm-1) resolution. A 25um slit would double that resolution and unfortunately reduce the signal by 50%. Maximizing the signal input, from the Raman probe, using fiber bundle circular-end to line-end is important when a slit is used.