Question

How to find antistokes wavelength if stokes and exciting line wavelength is given?

Answer 1

Stokes lines are of longer wavelength than that of the exciting radiation responsible for the fluorescence or Raman effect. 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).

Answer 2

Stokes lines, radiation of particular wavelengths present in the line spectra associated with fluorescence and the Raman effect (q.v.), named after Sir George Gabriel Stokes, a 19th-century British physicist. ... Thus, anti-Stokes lines are always of shorter wavelength than that of the light that produces them.