title: Image formation in fluorescence coherence-gated imaging through scattering media.
abstract: Recently, we have experimentally demonstrated a new form of cross-sectional, coherence-gated fluorescence imaging referred to as SD-FCT ('spectral-domain fluorescence coherence tomography'). Imaging in SD-FCT is accomplished by spectrally detecting self-interference of the spontaneous emission of fluorophores, thereby providing depth-resolved information on the axial positions of fluorescent probes. Here, we present a theoretical investigation of the factors affecting the detected SD-FCT signal through scattering media. An imaging equation for SD-FCT is derived that includes the effects of defocusing, numerical-aperture, and the optical properties of the medium. A comparison between the optical sectioning capabilities of SD-FCT and confocal microscopy is also presented. Our results suggest that coherence gating in fluorescence imaging may provide an improved approach for depth-resolved imaging of fluorescently labeled samples; high axial resolution (a few microns) can be achieved with low numerical apertures (NA<0.09) while maintaining a large depth of field (a few hundreds of microns) in a relatively low scattering medium (6 mean free paths), whereas moderate NA's can be used to enhance depth selectivity in more highly scattering biological samples.
authors.forename: A
authors.initials: A
authors.lastname: Bilenca
authors.forename: T
authors.initials: T
authors.lastname: Lasser
authors.forename: A
authors.initials: A
authors.lastname: Ozcan
authors.forename: R A
authors.initials: RA
authors.lastname: Leitgeb
authors.forename: B E
authors.initials: BE
authors.lastname: Bouma
authors.forename: G J
authors.initials: GJ
authors.lastname: Tearney