Freiburg 2024 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
Q: Fachverband Quantenoptik und Photonik
Q 52: Structured Light
Q 52.5: Talk
Thursday, March 14, 2024, 15:45–16:00, HS 1221
Optimized generation of maximally entangled photon pairs in orbital angular momentum by simultaneous pump and crystal engineering — •Richard Bernecker1,2, Baghdasar Baghdasaryan2,3, and Stephan Fritzsche1,2 — 1Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743, Jena, Germany — 2Helmholtz-Institut Jena, Fröbelstieg 3, 07743, Jena, Germany — 3Institut für Angewandte Physik, Friedrich-Schiller-Universität Jena, Albert-Einstein-Str. 6, 07745, Jena, Germany
Photon pairs generated from spontaneous parametric down-conversion (SPDC) are the predominant method to realize photonic entanglement. Laguerre-Gaussian modes, which carry orbital angular momentum (OAM), are commonly exploited to encode high-dimensional states experimentally. In particular, maximally entangled states (MES) in dimensions d>2 show promising features like improving the capacity and security of quantum communication protocols. However, the direct generation of MES in higher-dimensional subspaces of the OAM basis remains a challenging task in the SPDC process. The manipulation of entangled OAM states by shaping the spatial profile of the pump beam and the increase of the single-photon purity by customized crystal-domain configurations have been demonstrated lately. We combine these both approaches and show theoretically that simultaneous pump and crystal engineering enables the direct preparation of full MES within OAM subspaces of varying dimensions.
Keywords: Photon pairs; High-dimensional entanglement; Orbital angular momentum; Parametric down-conversion