Definition - What does Raman Spectroscopy mean?
Raman spectroscopy is a spectroscopic method that is utilized to observe rotational, vibrational and other modes of low frequency within a system. It works under the main principle of Raman scattering or inelastic scattering involving monochromatic light, typically from a near infrared light, ultraviolet light or laser.
This technique is used for chemical identification and other quantitative and qualitative applications.
Corrosionpedia explains Raman Spectroscopy
The Raman system is composed of four main components:
- Laser or excitation source
- Light collection optics and sample illumination system
- Spectrometer/filter as wavelength selector
- Photodiode array or detector
In Raman spectroscopy, inelastic scattering means that the photons' frequency under monochromatic light undergoes changes when exposed to a certain sample. The laser photons are soaked up by the sample and re-emitted. Then, the re-emitted photons' frequency is referred to as "Raman effect." This method can be used to evaluate gaseous, solid and liquid samples.
The spectra in this technique can be very specific and the identification of chemicals for corrosion analysis and other functions can be accomplished through searching algorithms alongside digital databases. Since Raman bands are sharper than their infrared counterparts, this can be used for a more accurate quantitative analysis.
Which method is best suited for a particular application depends on various factors like the solution or matrix, concentration level, sampling method and other existing species. For many applications, Raman spectroscopy can provide better answers for industrial monitoring needs and spectroscopic identification.