What is Raman scattering?

When the light travels with a solid, liquid or gas, some light will be dispersed and travels in instructions that differ from the light of the incoming light. Most of the scattered light retains their original frequency - it is known as an elastic scattering, Rayleigh dispersion is an example. A small portion of the scattered light will have a frequency less than the incoming light and an ever smaller ratio will have a higher frequency - this is called an inflexible dispersion. Raman's scattering is a form of non -lastic scattering and is named after Chandrasekkar Venkat Raman, who won the Nobel Prize for his work on this topic in 1930. When electromagnetic radiation, whose light is of the type, interacts with the molecule, can distort the shape of an electron cloud of the molecule; The extent in which this happens is known as the polarizability of the molecule and depends on the structure of the molecule and the nature of the bond between its atoms. After interacting with a light photo mThe shape of the electron cloud oscillate at the frequency related to the frequency of the incoming photon. This oscillation, in turn, causes the molecule to release a new photon at the same frequency, leading to elastic or Rayleigh scattering. The range in which Rayleigh and Raman differ depends on the polarizability of the molecule.

molecules can also vibrate, while the lengths of the bond between atoms grow periodically or reduce by 10%. If the molecule is in the lowest vibration state, sometimes the coming photon moves it to a higher vibration state, loses energy in the process and leads to the emitted photon has less energy and thus lower frequency. Less commonly molecule can be above its lowest vibration state, in which case the incoming photon could cause it to return to the lower state and gain energy that is emitted as a photon with a higher frequency.

This issue of photons with lower and higher frequency Je in the form of a non -non -aliasic scatter known as Raman's scattering. If the spectrum of scattered light is analyzed, the line is displayed on the incoming frequency due to the Rayleigh scattering, with smaller lines at lower frequencies and ever smaller lines at higher frequencies. These lower and higher frequency lines, known as the Stokes and Anti-Stokes, occur at the same intervals from the Rayleigh line and the overall pattern is characteristic of Raman's scattering.

Since the frequency intervals appear in which the lines of Stokes and Anti-Stokes appear, depending on the types of molecules that light interact with, Raman's dispersion can be used to determine the composition of the material sample. This technique is known as Raman's spectroscopy and usually uses a monochrome laser as a light source. Specific molecules create a unique formula of Stokes and Anti-Stokes, allowing them to identify them.