2025/02/05 by Cheng Li, Li, Cheng, Girish S. Kulkarni +15 · 2 citations
Biochemistry, Genetics and Molecular Biology · Engineering · Neuroscience · #Advanced Fluorescence Microscopy Techniques #FOS: Physical sciences #Optical Polarization and Ellipsometry #Optics (physics.optics) #Photoreceptor and optogenetics research #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2502.03586
openalex publication_date 2025/02/05 · openalex created_date 2025/02/08 · openalex updated_date 2026/08/01
Two-photon states generated from spontaneous parametric down-conversion (SPDC) can display entanglement in all degrees of freedom (DoFs) of light, including spatial, temporal, and polarization. The coupling between different DoFs of a two-photon state has been shown to display rich structures that enable novel and robust information processing schemes. While existing literature has studied these couplings by post-selecting the SPDC field, a comprehensive understanding of the inherent spatial-polarization coupling produced in the SPDC process is still lacking. This work produces a full spatial map of the polarization entanglement generated across the entire SPDC field. We observe an entire class of near-maximally polarization-entangled states with an average concurrence of 0.8303±0.0004, which, together with a certified spatial dimensionality of 148, could potentially offer access to a 251-dimensional hyperentanglement. The spatial-polarization coupling manifests as radially or linearly varying polarization-entangled states, whose wavefunctions are dependent on the transverse momenta of the down-converted photons and the pump beam, respectively. Our study lays important groundwork for further exploiting the coupling between entanglement in different DoFs for future quantum technologies.