Raman spectroscopy relies on the inelastic scattering of photons. The laser light interacts with molecular vibrations within a molecule, which shifts the energy of the light up and down, which alters the spectra of the returned light. Thus, creating a spectra of light, which is the signature of the molecule. However, the amount of light returned from inelastic scatter is very low compared with Rayleigh scattered light. In addition, for many materials the fluorescence that is induced in the material by the laser light swamps out the light from the inelastic scatter. Therefore, choosing the optimal wavelength to minimize fluorescence and maximize the signal from the molecules is critical in creating an effective Raman system. In addition, with the increasing emergence of spontaneous and enhanced Raman spectroscopy, creating an optimized laser source becomes progressively more important. Single-mode operation allows higher precision through your optical train.

Many Raman applications utilize 785, 830, and 1064 nm. Wavelengths in the NIR range are best for fluorescence suppression. Sheaumann has high-power, single-mode TO-Can and Butterfly packages that deliver reliable, continuous-wave power and best-in-class spectral performance at these critical wavelengths.