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Updated: May 25, 2026

Multimodal Volumetric Retinal Imaging by Oblique Scanning Laser Ophthalmoscopy (oSLO) and Optical Coherence Tomography (OCT)
Published on: August 4, 2018
Sub-Rayleigh optical vortex coronagraphy
E Mari1, F Tamburini, G A Swartzlander
1CISAS, University of Padua, I-35131 Padova, Italy. elettra.mari@unipd.it
Abstract:
We introduce a new optical vortex coronagraph (OVC) method to determine the angular distance between two sources when the separation is sub-Rayleigh. We have found a direct relationship between the position of the minima and the source angular separation. A priori knowledge about the location of the two sources is not required. The superresolution capabilities of an OVC, equipped with an ℓ = 2 N-step spiral phase plate in its optical path, were investigated numerically. The results of these investigations show that a fraction of the light, increasing with N, from the secondary source can be detected with a sub-Rayleigh resolution of at least 0.1 λ/D.
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