title: Contrast improvement in Fourier-domain optical coherence tomography through time gating.
abstract: Time-gated (TG) Fourier-domain optical coherence tomography (FDOCT) exploits interferometric imaging with incoherent gating to filter out unwanted backreflections and improve contrast. The system uses sum-frequency generation with a variable length optical pulse as a "time gate" to restrict the depth field of view of backscattered light to 84-176 microm (-20 dB points). The imaging bandwidth is upconverted from the IR (1280 nm) to visible (504 nm), which allows the use of sensitive silicon-based detection technology, prior to standard FDOCT processing. The TG system achieves a maximum sensitivity of 88 dB, and a contrast enhancement of 29 dB is shown over a standard IR FDOCT system. Imaging of a highly scattering medium (onion skin) is also demonstrated.
authors.affiliation: Department of Physics, Engineering Physics & Astronomy, Queen's University, Kingston, Ontario K7L 3N6, Canada.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Muller
authors.forename: James M
authors.initials: JM
authors.lastname: Fraser