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Complex Light and Optical Forces

Manipulation of entangled states of light using complex scattering process

Saroch Leedumrongwatthanakun, Natalia Herrera Valencia, Vatshal Srivastav, Suraj Goel, Will McCutcheon, Pepijn W. H. Pinkse, Claudio Conti, Mehul Malik

Published Mar 9, 2022• 0 citations
Publisher

Abstract

The development of high-quality photonic sources of high-dimensional entanglement and techniques for their manipulation is crucial for the advancement of quantum technologies. We present an efficient technique for generating and characterizing high-dimensional spatially entangled two-photon states with a record quality, dimensionality, and measurement speed. We demonstrate how to precisely manipulate such states by tailoring reprogrammable optical circuits in complex scattering media consisting of off-the-shelf multimode fiber and spatial light modulation. Our techniques open a clear pathway for the adoption of high-dimensional quantum states of light in the high-capacity, noise-robust quantum networks of tomorrow.

DOI
10.1117/12.2609615

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The development of high-quality photonic sources of high-dimensional entanglement and techniques for their manipulation is crucial for the advancement of quantum technologies. We present an efficient technique for generating and characterizing high-dimensional spatially entangled two-photon states with a record quality, dimensionality, and measurement speed. We demonstrate how to precisely manipulate such states by tailoring reprogrammable optical circuits in complex scattering media consisting of off-the-shelf multimode fiber and spatial light modulation. Our techniques open a clear pathway for the adoption of high-dimensional quantum states of light in the high-capacity, noise-robust quantum networks of tomorrow.
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Qudits have proven to be a powerful resource for quantum information processing, offering enhanced channel capacities, improved robustness to noise, and highly efficient implementations of quantum algorithms. The encoding of photonic qudits in transverse-spatial degrees of freedom has emerged as a versatile tool for quantum information processing, allowing access to a vast information capacity within a single photon. We examine recent advances in quantum optical circuits with spatially structured light, focusing particularly on top-down approaches that employ complex mode-mixing transformations in free space and fibers. We highlight circuits based on platforms such as multi-plane light conversion, complex scattering media, multi-mode, and multi-core fibers. We discuss their applications for the manipulation and measurement of multi-dimensional and multi-mode quantum states. Furthermore, we discuss how these circuits have been employed to perform multi-party operations and multi-outcome measurements, thereby opening new avenues for scalable photonic quantum information processing.
Abstract Programmable optical circuits are an important tool in developing quantum technologies such as transceivers for quantum communication and integrated photonic chips for quantum information processing. Maintaining precise control over every individual component becomes challenging at large scales, leading to a reduction in the quality of operations performed. In parallel, minor imperfections in circuit fabrication are amplified in this regime, dramatically inhibiting their performance. Here we use inverse design techniques to embed optical circuits in the higher-dimensional space of a large, ambient mode mixer such as a commercial multimode fibre. This approach allows us to forgo control over each individual circuit element, and retain a high degree of programmability. We use our circuits as quantum gates to manipulate high-dimensional spatial-mode entanglement in up to seven dimensions. Their programmability allows us to turn a multimode fibre into a generalized multioutcome measurement device, allowing us to both transport and certify entanglement within the transmission channel. With the support of numerical simulations, we show that our method is a scalable approach to obtaining high circuit fidelity with a low circuit depth by harnessing the resource of a high-dimensional mode mixer.