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Static depth dependent dispersion compensation in a real-time static delay line grating-based correlation OCT system. L. Froehly, P. Sandoz, L. Furfaro, M.Ouadour Institut FEMTO-ST; Département d’Optique P.M. Duffieux Besançon, France. 100 m m. Dispersion problem in OCT.
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Static depth dependent dispersion compensation in a real-time static delay line grating-based correlation OCT system L. Froehly, P. Sandoz, L. Furfaro, M.Ouadour Institut FEMTO-ST; Département d’Optique P.M. Duffieux Besançon, France ECBO 2007
100mm Dispersion problem in OCT • Dispersion limits axial resolution • Dispersion depends on the material thickness • Dispersion decreases the Signal to Noise ratio ECBO 2007
S.L.S. O1 S1 M1 O2 Hardware correction ECBO 2007
Hardware correction (rapid scanning delay line) Rollins, S. Yazdanfar, M. Kulkarni, R. Ung-Arunyawee, and J. Izatt, Opt. Express 3, 219-229 (1998) K. F. Kwong, D. Yankelevich, K. C. Chu, J. P. Heritage, and A. Dienes, Opt. Lett. 18, 558- (1993) ->first demonstration for pulse measurements G. J. Tearney, B. E. Bouma, and J. G. Fujimoto, Opt. Lett. 22, 1811-1813 (1997) ->Application of the system to TD-OCT system ECBO 2007
Numerical correction • Phase correction in Fourier space • Influence of the phase correction on the image contrast • Quite time consuming ECBO 2007
y z Grating-based Tomographic system L1 D Il(z) S.L.S. M2 M..: Mirror S: Polarizing beam splitter L1: Spherical lens S.L.S. : White light laser source C.B. : Polarizing beam splitter D : CCD R : Diffraction grating 530 gr/mm P : prism O…: Miroscope objectives E : Sample O1 S1 R P zt M3 C.B. O2 ECBO 2007
I x↔z Principle M2 R M3 ECBO 2007
Absorption L1 D Il(z) S.L.S. M2 O1 S1 R P zt M3 C.B. O2 y z L. Froehly, M. Ouadour, L. Furfaro, P. Sandoz, T. Gharbi et al, Real-time optical coherence spectrotomography : proof of principle volume 6191 of Biophotonics and New Therapy Frontiers. SPIE, Apr. 2006. ECBO 2007
z Optical Depth dependant dispersion compensation z z ECBO 2007
Optical Depth dependant dispersion compensation : principle ECBO 2007
Optical Depth dependant dispersion compensation : principle ECBO 2007
Optical Depth dependant dispersion compensation : principle ECBO 2007
Optical Depth dependant dispersion compensation : validation ECBO 2007
Optical Depth dependant dispersion compensation : validation ECBO 2007
Optical Depth dependant dispersion compensation : validation ECBO 2007
Optical Depth dependant dispersion compensation : validation ECBO 2007
S.L.S. D M2 O1 S1 R P M3 C.B. O2 y z Future directions : catadioptrics systems ECBO 2007
Aknowldegments • French ANR who finances this project • Leukos innovative systems who provide us with microchip-based supercontinuums ECBO 2007