Raman amplification spectroscopy

Abstract

The main experimental and theoretical developments in Raman amplification spectroscopy (RAS, common term for stimulated Raman gain and stimulated Raman loss or inverse Raman spectroscopies) are reviewed. In the theoretical section the Raman amplification process is briefly described, and the dependence of the signal-to-noise ratio on the molecular and experimental parameters is discussed. The experimental results demonstrate that RAS has become a method of great importance. Thus, using high power single mode lasers Doppler limited high resolution spectra have been obtained. The introduction of picosecond lasers has lead to a dramatic improvement in the sensitivity. RAS provides a very efficient fluorescence rejection. Exploiting its high temporal resolution capability short lived species and transient states can be studied.