We describe a novel technique for contrast enhancement in optical coherence tomography (OCT) that makes possible molecular-specific imaging for what is believed to be the first time. A pump–probe technique is employed in which a pulsed pump laser is tuned to ground-state absorption in a molecule of interest. The location of the target molecule population is derived from the resulting transient absorption of OCT sample-arm light acting as probe light. A signal processing technique for three-dimensional localization of the transient absorption signal is described, and preliminary results exhibiting OCT contrast from methylene blue dye in multilayer and scattering phantoms are presented.
© 2003 Optical Society of America
(170.3890) Medical optics and biotechnology : Medical optics instrumentation
(170.4500) Medical optics and biotechnology : Optical coherence tomography
(190.0190) Nonlinear optics : Nonlinear optics
K. Divakar Rao, Michael A. Choma, Siavash Yazdanfar, Andrew M. Rollins, and Joseph A. Izatt, "Molecular contrast in optical coherence tomography by use of a pump probe technique," Opt. Lett. 28, 340-342 (2003)