Improved lateral resolution in optical coherence tomography by digital focusing using two-dimensional numerical diffraction method.

This paper proposes a non-iterative, two-dimensional numerical method to eliminate the compromise between the lateral resolution and wide depth measurement range in optical coherence tomography (OCT). A two-dimensional scalar diffraction model was developed to simulate the wave propagation process from out-of-focus scatters within the short coherence gate of the OCT system. High-resolution details can be recovered from outside of the depth-of-focus region with minimum loss of lateral resolution. Experiments were performed to demonstrate the effectiveness of the proposed method.