Full spectroscopic identification of molecules has been hampered by the inability to use an information-rich spectroscopic method such as Raman scattering in a flowing aerosol environment due to the time needed to generate a Raman spectrum. Multiplex coherent anti-Stokes Raman spectroscopy (MCARS) has been shown to generate a complete Raman spectrum from the material of interest using a single ultrabroadband pulse to coherently drive multiple molecular vibrations simultaneously. When used in conjunction with a narrow probe pulse, a complete Raman spectrum is created that can be detected in milliseconds. We will report on the MCARS spectra obtained from materials of interest at a distance of 1 m from the sample location. We will also be reporting on an analytical method to remove the nonresonant background that utilizes a combination of the maximum entropy method to reproduce the spectrum as well as complex spectral filtering to remove the nonresonant background and accurately determine the CARS spectrum interest without prior knowledge of the material of interest.
© 2015 Optical Society of AmericaPDF Article