Blur resolved OCT: full-range interferometric synthetic aperture microscopy through dispersion encoding.

In this work, we present methods for full-range interferometric synthetic aperture microscopy (ISAM) under dispersion encoding. With this, one can effectively double the depth range of optical coherence tomography (OCT), whilst dramatically enhancing the spatial resolution away from the focal plane. To this end, we propose two algorithms: a two-step greedy approach building upon the dispersion encoded full-range (DEFR) method; and a model-based iterative reconstruction (MBIR), where ISAM is directly considered in an optimization approach, and we make the discovery that sparsity promoting regularisation effectively recovers the full-range signal. While the greedy approach achieves rapid real-time processing, exceeding 2 kHz A-scan throughput, MBIR achieves a qualitative enhancement of structural clarity and noise suppression. Within this work, we adopt an optimal nonuniform discrete fast Fourier transform (NUFFT) implementation of ISAM, which is both fast and numerically stable throughout iterations. We validate our methods in 2D and 3D with several complex samples, scanned with a commercial SD-OCT system with no hardware modification.