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Quantum 2.0 Conference and Exhibition

Portable swappable polarization-entanglement sources

Tiphaine Kouadou, David Diaz, Paul G. Kwiat

Published Jan 1, 2023• 0 citations
Publisher

Abstract

We present a dual source of swappable entanglement in the near infrared for local quantum networking and free-space quantum links. Built on portable platforms, the polarization-entangled photons are generated via spontaneous parametric down conversion in two adjacent fiber-pigtailed type-II PPKTP waveguides.
DOI
10.1364/quantum.2023.qw4c.3

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We present integrated sources of polarization entanglement built on portable platforms for quantum communication. We employ type-II degenerate spontaneous parametric down conversion processes in PPKTP waveguides to generate pairs of orthogonally polarized photons at near-infrared wavelengths. The photons are sent to a 50/50 non-polarizing beam splitter (NPBS) to generate post-selected polarization-entangled states via coincidence measurements. The small size of the waveguides allows the installation of several units on the same platform, and thereby the generation of multiple entangled states simultaneously. We use a computer-controlled tomography system to characterize the produced states and combine the photons from adjacent waveguides on another NPBS to perform Bell-state measurements, a prerequisite to entanglement swapping. The overall experiment is compact and requires little alignment when set, making it an attractive option for local quantum networking using mobile platforms, e.g., drones or satellites.
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