Laser Raman Spectroscopy

Laser Raman Spectroscopy

Technique:

Laser Raman spectroscopy depends on a change in the polarization of a molecule to produce Raman scattering. When a beam of photons strikes a molecule, the photons are scattered elastically (Rayleigh scattering) and inelastically (Raman scattering) generating Stoke’s and anti-Stokes lines.

Because Raman spectroscopy is a scattering process, samples of any size or shape can be examined. Very small amounts of material can be studied down to microscopic levels (~1µm).

Instrument:

Renishaw InVia Reflex Raman Spectrometer with three wavelengths available: 785nm, 633nm and 514nm and two gratings, 1800 and 1200 l/mm. Also equipped with polarizer and half waveplate for each laser.

System Accessories:

• Microscope with Macro Point Accessory Kit, allowing analysis of powders, liquids, and films
• StreamLine HR imaging, a high speed mapping function allowing the collection of thousands of datapoints in minutes. Minimum step size, 0.1 microns.
• StreamLine imaging, allowing the collection of spatially resolved spectra with longer accumulation times.
• Volume rendering (StreamLine HR acquisition)
• Depth profiling

Selected Applications in Industry:]

• Differentiation of carbon nanotube species (SWCNT, MWCNT)
• Identification of corrosion products on various metal surfaces
• Identification of different forms of carbon (e.g. diamond, graphitic, amorphous, diamond-like, nanotubes)
• Detection of different inorganic oxides and, in some instances, their crystal form
• Identification of micron-sized contaminants on photomasks
• Identification of pigments in some paints and inks