Open AccessDirect observation of OAM correlations from spatially entangled bi-photon states
Author(s) -
Zeferino Ibarra-Borja,
Carlos Sevilla-Gutiérrez,
Roberto Ramírez-Alarcón,
Qiwen Zhan,
Héctor Cruz-Ramírez,
Alfred B. U’Ren
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.025228
Subject(s) - physics , photon , optics , topological quantum number , photon entanglement , angular momentum , spontaneous parametric down conversion , photon polarization , signal (programming language) , quantum entanglement , quantum mechanics , quantum , computer science , programming language
We present spatially-resolved observations of orbital angular momentum (OAM) conservation, via a Laguerre-Gauss (LG) basis decomposition, of spatially-entangled photon pairs produced in type-I collinear spontaneous parametric downconversion (SPDC). These results were obtained with a novel detection system for OAM-entangled photon pairs that combines a projective measurement for the signal photon to a specific value of the azimuthal index ls, with a spatially-resolved measurement for the idler photon using an intensified charge coupled (ICCD) camera. In combination with far-field diffraction of the idler photon through a triangular aperture, we are able to obtain: i) the spatial structure of the heralded idler photon, as governed by the user-selected topological charge of the signal photon; ii) the OAM spectrum; and iii) the topological charge (both magnitude and sign) for the heralded idler photon.