High Sensitivity Conherent Anti-Stokes Raman Scattering for Linearly Probing Low Concentration Materials

The authors made a theoretical analysis and experiment research on the relation of time-resolved coherent anti-Stokes Raman scattering(T-CARS) intensity and the sample concentrations in this paper.It was proved experimentally that the T-CARS intensity is quadratic at the concentrationhigher than 35%,but is linear with the sample concentration at the concentration lower than 20%,which fits with theoretical analysis.And the research results correct inaccurate previous perceptions,which is conducive to better interpretation and application of the CARS process.The linear relation between the intensity of the CARS with the sample concentration at low concentrations indicates that the CARS is allowed for direct and precise concentration measurements,therefore it will be of great importance in biology and biochemistry.