title: Probing molecular absorption under slow-light propagation using a photonic crystal waveguide.
abstract: High-resolution infrared absorption spectroscopy of acetylene gas is demonstrated in a dispersion-engineered photonic crystal waveguide under slow-light propagation. Experimental enhancement factors of 0.31 and 1.00 are obtained for TE and TM polarization, respectively, for group indices ranging from 1.5 to 6.7. The dependence of molecular absorption on the evanescent electric-field distribution and on the group index under structural slow-light illumination is experimentally demonstrated and confirmed by time-domain simulations.
authors.affiliation: École Polytechnique Fédérale de Lausanne (EPFL), Institute of Electrical Engineering, STI-GR-SCI-LT Station 11, Lausanne 1015, Switzerland.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Dicaire
authors.forename: Alfredo
authors.initials: A
authors.lastname: De Rossi
authors.forename: Sylvain
authors.initials: S
authors.lastname: Combrié
authors.forename: Luc
authors.initials: L
authors.lastname: Thévenaz