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arXiv · 2510.07781

Super resolving binary-source hypothesis testing with a double-clad fiber coupler

John S. Wallis·David R. Gozzard·Alex M. Frost·Benjamin P. Dix-Matthews·Nicolas Maron·Joshua J. Collier
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Abstract

We present a technique for binary spatial mode demultiplexing, using a double-clad fiber coupler as an optical mode sorter, for hypothesis testing for one or two point sources in an incident optical field. By directly coupling an optical field through a double-clad fiber coupler, we demultiplex the field into the fundamental mode and a superposition of higher-order modes. We use the ratio of multi-mode to single-mode power to distinguish between single and double point sources. In a tabletop demonstration of the technique, we demonstrate the capability to accurately identify the presence of two sources separated below the Rayleigh limit for relative brightnesses from 0 dB to -20 dB. For sources with less than 5 dB difference in their relative powers, our imaging protocol can correctly determine the presence of a second optical source even when the two sources have separations 50x smaller than the Rayleigh limit. These results highlight the potential of this technique as a simple tool for super-resolving classification of a pair of point emitters, especially in the context of astronomical imaging for binary systems.

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John S. Wallis, David R. Gozzard, Alex M. Frost, Benjamin P. Dix-Matthews, Nicolas Maron, Joshua J. Collier. 2025-10-09. Super resolving binary-source hypothesis testing with a double-clad fiber coupler. https://arxiv.org/abs/2510.07781

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