Table of Contents
- 1 How do you calculate Stokes wavelength?
- 2 What is the energy level for anti-Stokes lines?
- 3 How would you intensify anti Stokes lines in Raman spectra?
- 4 What are Stokes and anti Stokes lines Why is the intensity of Stokes lines generally greater than that of anti Stokes lines?
- 5 What are Stokes and anti-Stokes lines Why is the intensity of Stokes lines generally greater than that of anti-Stokes lines?
- 6 Why Stokes lines are more intense than anti Stokes lines?
How do you calculate Stokes wavelength?
Most recent answer
- Stokes shift usually calculates in wavenumber (unit = cm-1).
- Convert to wavelength (nm) to wavenumber (cm-1) [for that, abs 307 nm = 107/307 cm-1 = 32573.29 cm-1 , emi 469 nm = 107/469 cm-1 = 21321.96 cm-1 ,]
- Stokes shift = Absorption (wavenumber) – Emission(wavenumber)
What is the energy level for anti-Stokes lines?
Anti-Stokes lines are found in fluorescence and in Raman spectra when the atoms or molecules of the material are already in an excited state (as when at high temperature). In this case the radiated line energy is the sum of the pre-excitation energy and the energy absorbed from the exciting radiation.
What is Raman effect formula?
By further investigating the quantum interpretation of the Raman effect, it can be shown that the power of the scattered light, Ps, is equal to the product of the intensity of the incident photons, Io, and a value known as the Raman cross-section, σR. It can be shown that, Equation R-9.
How is fluorescence related to the Stokes shift?
Why is it called the Stokes Shift? This is Stokes’ Law and states that the fluorescence emission occurs at a longer wavelength than the incident light. The shift to longer wavelength between the absorption and fluorescence spectra is accordingly called the Stokes shift in his honour.
How would you intensify anti Stokes lines in Raman spectra?
Raising the temperature would decrease the population of the ground state and increase the population of higher energy vibrational states. Therefore, with increased temperature, the intensity of the Stokes lines would decrease and the intensity of the anti-Stokes lines would increase.
What are Stokes and anti Stokes lines Why is the intensity of Stokes lines generally greater than that of anti Stokes lines?
As the number of atoms in the ground state is more than the number of atoms in the excited states, the Stokes lines are more intense than the anti Stokes lines.
Why are anti Stokes lines less intense than Stokes lines?
The anti-Stokes lines will be much weaker than the Stokes lines because there are many more molecules in the ground state than in excited vibrational states.
What is the difference between Stokes and anti-Stokes?
When the radiation is absorbed, a molecule jumps to a higher vibrational or rotational energy level. If the emitted radiation is of lower frequency than the incident radiation, then it is called Stokes scattering. If it is of higher frequency, then it is called anti-Stokes scattering.
What are Stokes and anti-Stokes lines Why is the intensity of Stokes lines generally greater than that of anti-Stokes lines?
Why Stokes lines are more intense than anti Stokes lines?
Nevertheless, Stokes lines are more intense in comparison with the anti-Stokes counterparts, because the vibrational ground state is more populated than excited states.
What is Raman effect of class 9th?
The Raman Effect is the process of scattering of light particles by molecules of a medium. The scattering occurs due to a change in the wavelength of light as it enters the medium. Light consists of particles called photons, whose energy is directly proportional to the frequency with which they travel.