A compact fiber-laser-based system for detection of biological agents via coherent Raman spectroscopy

Abstract

We report on a compact laser system for detection of hazardous biological agents by standoff coherent anti-Stokes Raman spectroscopy (CARS). The system is based on ytterbium-laser technology featuring broad spectral coverage and high sensitivity. High-quality CARS spectra have been obtained for NaDPA powder, a substitute for CaDPA, which is the Raman marker of bacterial spores. In addition, endospores of B. atrophaeus deposited over a glass substrate have been detected by their CARS signature at a standoff distance of 1 m and an integration time of 1 s. The system will be further developed for imaging of bacterial spores deposited over wide surface areas at standoff distances.