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Nonlinear Optics

Nanoscale Spontaneous Parametric Down-Conversion

Maria V. Chekhova

Published Jan 1, 2021• 0 citations
Publisher

Abstract

We generate entangled photons via spontaneous parametric down-conversion (SPDC) in subwavelength films of nonlinear materials and all-dielectric nonlinear metasurfaces. The SPDC spectra reveal resonances: Fabry-Perot in the first case and Mie in the second case.
DOI
10.1364/nlo.2021.nm2b.1

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All-dielectric optical metasurfaces are a workhorse in nano-optics due to both their ability to manipulate light in different degrees of freedom and their excellent performance at light frequency conversion. Here, we demonstrate first-time generation of photon pairs via spontaneous parametric-down conversion in lithium niobate quantum optical metasurfaces with electric and magnetic Mie-like resonances at various wavelengths. By engineering the quantum optical metasurface, we tailor the photon-pair spectrum in a controlled way. Within a narrow bandwidth around the resonance, the rate of pair production is enhanced up to two orders of magnitude compared to an unpatterned film of the same thickness and material. These results enable flat-optics sources of entangled photons -- a new promising platform for quantum optics experiments.