title: Real time en face Fourier-domain optical coherence tomography with direct hardware frequency demodulation.
abstract: We demonstrate en face swept source optical coherence tomography (ss-OCT) without requiring a Fourier transformation step. The electronic optical coherence tomography (OCT) interference signal from a k-space linear Fourier domain mode-locked laser is mixed with an adjustable local oscillator, yielding the analytic reflectance signal from one image depth for each frequency sweep of the laser. Furthermore, a method for arbitrarily shaping the spectral intensity profile of the laser is presented, without requiring the step of numerical apodization. In combination, these two techniques enable sampling of the in-phase and quadrature signal with a slow analog-to-digital converter and allow for real-time display of en face projections even for highest axial scan rates. Image data generated with this technique is compared to en face images extracted from a three-dimensional OCT data set. This technique can allow for real-time visualization of arbitrarily oriented en face planes for the purpose of alignment, registration, or operator-guided survey scans while simultaneously maintaining the full capability of high-speed volumetric ss-OCT functionality.
authors.affiliation: Lehrstuhl für BioMolekulare Optik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Munich, Germany.
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Biedermann
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wieser
authors.forename: Christoph M
authors.initials: CM
authors.lastname: Eigenwillig
authors.forename: Gesa
authors.initials: G
authors.lastname: Palte
authors.forename: Desmond C
authors.initials: DC
authors.lastname: Adler
authors.forename: Vivek J
authors.initials: VJ
authors.lastname: Srinivasan
authors.forename: James G
authors.initials: JG
authors.lastname: Fujimoto
authors.forename: Robert
authors.initials: R
authors.lastname: Huber
mesh_terms: D003199:Computer Systems; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D041623:Tomography, Optical Coherence / Q000295:instrumentation*