Laterally oranges super-resolving optical coherence tomography by intentional defocus and numerical compensation

A method of lateral superresolution for Fourier domain optical coherence tomography is presented. This method consists of intentional defocus and its numerical compensation using a spatial frequency- phase filter. The designing process of the phase filter is described, and the superresolution effect is discussed theoretically. Experimental results of knife-edge test prove that the frequency filter enhances the lateral resolution better than a trans-form limited resolution.