Compact 2D nonlinear photonic crystal source of beamlike path entangled photons

Abstract

We demonstrate a method to generate entangled photons with controlled spatial\nshape by parametric down conversion (PDC) in a 2D nonlinear crystal. A compact\nand novel crystal source was designed and fabricated, generating directly path\nentangled photons without the use of additional beam-splitters. This crystal\nsupports two PDC processes, emitting biphotons into two beamlike modes\nsimultaneously. Two coherent path entangled amplitudes of biphotons were\ncreated and their interference observed. Our method enables the generation of\nentangled photons with controlled spatial, spectral and polarization\nproperties.\n