We describe and experimentally demonstrate a novel (to our knowledge) surface profiling technique, for which we propose the term closed-loop optical coherence topography. This technique is a scanning beam, servo-locked variation of low-coherence interferometry. It allows for the sub-wavelength-resolution tracking of a weakly scattering macroscopic-scale surface, with the surface profile being directly output by the controlling electronics. The absence of significant real-time computational overhead makes the technique well suited to high-speed tracking. The use of a micrometer-scale coherence gate efficiently suppresses signals arising from structures not associated with the surface. These features make the technique particularly well suited to real-time surface profiling of <i>in vivo</i>, macroscopic biological surfaces.
© 2002 Optical Society of America
(110.4500) Imaging systems : Optical coherence tomography
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.6650) Instrumentation, measurement, and metrology : Surface measurements, figure
(170.1650) Medical optics and biotechnology : Coherence imaging
Andrei V. Zvyagin, Ilos Eix, and David D. Sampson, "High-Speed, High-Sensitivity, Gated Surface Profiling with Closed-Loop Optical Coherence Topography," Appl. Opt. 41, 2179-2184 (2002)