Determination of absolute Raman cross-section of chemicals and explosives using swept wavelength resonance Raman device *

Multi-wavelength resonance Raman in UV has been emerged as an important spectroscopic tool for detection of chemicals and explosives. We have used SWOrRD (Swept Wavelength Optical Resonance Raman Device) to detect chemical and hazardous materials. Using these SWOrRD-derived Raman data, we have determined the excitation-energy dependence of Raman cross-section in the range 220-280 nm for various chemical samples such as KClO₄, KNO₃, KSO₄ and CH₅N₃O₄. We also investigated the pre-resonance and resonance Raman enhancement of these samples. The knowledge of specific excitation wavelength can be utilized to selectively enhance the desired Raman band of the molecules and help to choose the right excitation laser which is useful for real time standoff detection of explosives and chemicals.