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Published on: October 2, 2021
Contrast improvement in Fourier-domain optical coherence tomography through time gating
Matthew S Muller1, James M Fraser
1Department of Physics, Engineering Physics & Astronomy, Queen's University, Kingston, Ontario K7L 3N6, Canada.
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.
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