A full-vectorial theoretical investigation of the recently proposed background-free coherent anti-Stokes Raman scattering (CARS) spectroscopy near transverse interfaces [ Phys. Rev. A, 77, 061802(R) (2008) ] is presented. In this scheme, the field symmetries of the focused excitation beams are applied to recover the pure Raman spectrum of a medium forming a transverse interface with a nonresonant medium. We show that this method is robust to spatial shift of the excitation volume relative to the interface and does not depend on the linear polarizations states of the pump and Stokes beams. Finally, we extend the applicability of this scheme to a succession of planar interfaces between resonant and nonresonant media, which is potentially interesting for fast chemical analysis in microfluidic devices. Interestingly, this method can be extended to nondegenerated resonant four-wave-mixing processes to remove the nonresonant background.
© 2008 Optical Society of America
Original Manuscript: May 28, 2008
Manuscript Accepted: July 30, 2008
Published: September 18, 2008
Vol. 3, Iss. 12 Virtual Journal for Biomedical Optics
David Gachet, Franck Billard, and Hervé Rigneault, "Background-free coherent anti-Stokes Raman spectroscopy near transverse interfaces: a vectorial study," J. Opt. Soc. Am. B 25, 1655-1666 (2008)