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arXiv · 2509.03349

Low-coherence interferometry with undetected mid-infrared photons in the high-gain regime

Giovanni Zotti·Dmitri B. Horoshko·Mikhail I. Kolobov·Yoad Michael·Ziv Gefen·Maria V. Chekhova·Kazuki Hashimoto
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Abstract

We develop a high-parametric-gain SU(1,1) interferometer based on an aperiodically poled Potassium Titanyl Phosphate (apKTP) crystal, enabling frequency-domain low-coherence interferometry with undetected mid-infrared photons. The system achieves a signal-to-noise ratio as high as 40 dB and axial resolution of 30 $\mu$m, with a 3 $\mu$m-centered idler beam. By increasing the poling-period range, we also improve the axial resolution to 17 $\mu$m, demonstrating a straightforward route to enhance the performance by working on the crystal design

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Giovanni Zotti, Dmitri B. Horoshko, Mikhail I. Kolobov, Yoad Michael, Ziv Gefen, Maria V. Chekhova, Kazuki Hashimoto. 2025-09-03. Low-coherence interferometry with undetected mid-infrared photons in the high-gain regime. https://doi.org/10.1364/ol.578129

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