"High-speed polarization sensitive optical coherence tomography scan engine based on Fourier domain mode locked laser"Marco Bonesi, Harald Sattmann, Teresa Torzicky, Stefan Zotter, Bernhard Baumann, Michael Pircher, Erich Götzinger, Christoph Eigenwillig, Wolfgang Wieser, Robert Huber, and Christoph K. Hitzenberger
Biomedical Optics Express, Vol. 3, Issue 11, pp. 2987-3000 (2012)
We report on a new swept source polarization sensitive optical coherence tomography scan engine that is based on polarization maintaining (PM) fiber technology. The light source is a Fourier domain mode locked laser with a PM cavity that operates in the 1300 nm wavelength regime. It is equipped with a PM buffer stage that doubles the fundamental sweep frequency of 54.5 kHz. The fiberization allows coupling of the scan engine to different delivery probes. In a first demonstration, we use the system for imaging human skin at an A-scan rate of 109 kHz. The system illuminates the sample with circularly polarized light and measures reflectivity, retardation, optic axis orientation, and Stokes vectors simultaneously. Furthermore, depolarization can be quantified by calculating the degree of polarization uniformity (DOPU). The high scanning speed of the system enables dense sampling in both, the x- and y-direction, which provides the opportunity to use 3D evaluation windows for DOPU calculation. This improves the spatial resolution of DOPU images considerably.
BMO authors (in alphabetic order):
Optical Coherent Ranging and Optical Coherence Tomography (OCT): Imaging and profilometry with rapidly frequency swept laser sources
Fourier Domain Mode Locking (FDML): Spectral mode locking in optics and applications