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Super-Resolution Optical Coherence Tomography (OCT)

Investigators: Rajesh Langoju, Thierry Blu

Summary: We use a model-based approach to push the resolution of OCT beyond the coherence-length limit. We reformulate the imaging task as a parameter-estimation problem, and derive some corresponding algorithms.


Optical Coherence Tomography (OCT) is a recent high-resolution imaging technique based on an interferometric measure in which a wave with low temporal coherence is split into two parts. One of the beams hits the sample, is backscattered, and guided to a photodetector where it interferes with the second beam which acts as a reference wave. By varying the pathlength of the reference wave, one is able to scan inside the object at depths such that the backscattered wave stays coherent with the incident one.

Main Contributions

Retrieving the optical parameters of the object from the OCT measure is an inverse problem for which we have formulated a new exact solution. Our preliminary validation results show that the resolution depth of the reconstructed object depends on the signal-to-noise ratio of the OCT data, and not on the temporal coherence of the illuminating source—contrary to the classical OCT theory.

Collaborations: Prof. Michael Unser, Dr. Philippe Bourquin (LOA-EPFL), Prof. René-Paul Salathé (LOA-EPFL), Prof. Théo Lasser (LOB-EPFL)

Period: 2002-2005

Major Publication


T. Blu, H. Bay, M. Unser, "A New High-Resolution Processing Method for the Deconvolution of Optical Coherence Tomography Signals," Proceedings of the First IEEE International Symposium on Biomedical Imaging: Macro to Nano (ISBI'02), Washington DC, USA, July 7-10, 2002, vol. III, pp. 777-780.

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© 2013 EPFL • • 16.12.2013