Rodrigo Gomez | Searcharxiv

arXiv2024

Polarization-entangled photon pair source using beam displacers and thin crystals

We present an experimental implementation of a polarization-entangled photon pair source based on beam displacers. The down-converted photons are emitted via spontaneous parametric down-conversion in a non-degenerate and type-0 process. We obtain a state fidelity of $F=0.975\pm0.004$ and violate a Clauser-Horne-Shimony-Holt inequality with $S=2.75\pm0.01$. Our source also uses thin crystals for applications in quantum imaging, taking advantage of the large number of spatial modes. We estimate that our source could produce 550$\pm$12 spatial modes.

quant-ph↗

arXiv2023

Resolving Photon Numbers Using Ultra-High-Resolution Timing of a Single Low-Jitter Superconducting Nanowire Detector

Photon-number-resolving (PNR) detectors are a key enabling technology in photonic quantum information processing. Here, we demonstrate the PNR capacity of conventional superconducting nanowire single-photon detectors by performing ultra-high-resolution time-tagging of the detector-generated electrical pulses. This method provides a viable approach for PNR with high detection efficiency and a high operational repetition rate. We present the implementation of such a PNR detector in the telecom C-band and its characterization by measuring the photon-number statistics of coherent light with tunable intensity. Additionally, we demonstrate the capabilities of the detection method by measuring photon-number correlations of non-classical states.

quant-ph↗