Enhancement of Raman Spectral Intensities:

Raman lines are intrinsically extremely weak.  You would recall which only 1 in 10⁷ of the scattered photons causes the Stokes and anti-Stokes signals. It is since of this weak spectra and unavailability of powerful source, which Raman spectroscopy was not much used  for  the  structural  studies  till  about  1960  while  intense  laser  sources  became available. The intrinsic weakness of the spectra needed high concentrations (~0.1M) of the analyte that additional limited its applications.  Once the problem of intense source was solved, there have been efforts to further improve the spectral intensities, so as to be able to analyse the analytes at lower concentrations.  This could be achieved while tunable dye lasers became available. Let us learn about a few methods for enhancing the spectral intensities and the principles behind them.