Optical coherence tomography (OCT) with unprecedented submicrometer axial resolution achieved by use of a photonic crystal fiber in combination with a compact sub-10-fs Ti:sapphire laser (Femtolasers Produktions) is demonstrated for what the authors believe is the first time. The emission spectrum ranges from 550 to 950 nm (λ<sub>c</sub>=725 nm , <i>P</i><sub>out</sub>=27 mW) , resulting in a free-space axial OCT resolution of ~0.75 μm , corresponding to ~0.5 μm in biological tissue. Submicrometer-resolution OCT is demonstrated <i>in vitro</i> on human colorectal adenocarcinoma cells HT-29. This novel light source has great potential for development of spectroscopic OCT because its spectrum covers the absorption bands of several biological chromophores.
© 2002 Optical Society of America
(060.7140) Fiber optics and optical communications : Ultrafast processes in fibers
(110.4500) Imaging systems : Optical coherence tomography
(170.3880) Medical optics and biotechnology : Medical and biological imaging
(190.4370) Nonlinear optics : Nonlinear optics, fibers
B. Povazay, K. Bizheva, A. Unterhuber, B. Hermann, H. Sattmann, A. F. Fercher, W. Drexler, A. Apolonski, W. J. Wadsworth, J. C. Knight, P. St. J. Russell, M. Vetterlein, and E. Scherzer, "Submicrometer axial resolution optical coherence tomography," Opt. Lett. 27, 1800-1802 (2002)