Does Raman spectroscopy use visible light?

Numerous different wavelengths of light are commonly used in Raman spectroscopy, ranging from the ultraviolet (UV) through the visible, and into the near-infrared (near-IR). Choosing the best illumination wavelength for a given application is not always obvious.

Which is the most commonly used laser for Raman spectroscopy?

The most commonly used laser wavelength in Raman spectroscopy is 785 nm which offers low fluorescence whilst retaining relatively high Raman intensity.

What is Raman spectroscopy based on?

Raman Spectroscopy is a non-destructive chemical analysis technique which provides detailed information about chemical structure, phase and polymorphy, crystallinity and molecular interactions. It is based upon the interaction of light with the chemical bonds within a material.

Why IR and Raman spectroscopy are complementary techniques?

The label-free noninvasive molecular spectroscopy enables us to acquire bond-specific chemical information of specimen, and it is known that infrared (IR) absorption and Raman scattering spectroscopy provide complementary information of molecular vibrations: the former is active for anti-symmetric vibrations that alter …

What do you need to consider when choosing the excitation wavelength for Raman spectroscopy?

The frequency of the light is inversely proportional to the wavelength, and so all other things being equal, the shorter excitation wavelength will yield a stronger Raman signal. That is one of the reasons why, when given a choice, Raman spectroscopists prefer shorter excitation wavelengths.

What would be the ideal source to use for measuring Raman spectra?

laser
That means that a laser would be preferable as a source for measuring Raman spectra. The highly monochromatic emission from a laser also means that we can more accurately measure the frequency of the Stokes lines in the resulting spectrum.

What are the applications of Raman spectroscopy?

Most common applications of Raman spectroscopy Whether the goal is qualitative or quantitative data, Raman analysis can provide key information easily and quickly. It can be used to rapidly characterize the chemical composition and structure of a sample, whether solid, liquid, gas, gel, slurry or powder.

What can Raman spectroscopy not detect?

Lack of signal cannot identify a compound, but it can be characterized. Sometimes a Raman signal is overwhelmed by (1) high fluorescence or heat, but more commonly lack of Raman signal suggests (2) water, (3) metals, (4) elements, and/or (5) simple ionic compounds could be the issue.

Why does Raman scattering occur?

Raman effect, change in the wavelength of light that occurs when a light beam is deflected by molecules. When a beam of light traverses a dust-free, transparent sample of a chemical compound, a small fraction of the light emerges in directions other than that of the incident (incoming) beam.

Is Raman spectroscopy a vibrational spectroscopy?

Vibrational Raman spectroscopy is the Raman technique most widely used in chemical analysis, and it is relevant for the characterization of molecules in solution, biomolecules, and solids (crystals and powders).