title: Generation of entangled photon pairs using small-coherence-time continuous wave pump lasers.
abstract: We address the generation of entangled photon pairs by parametric downconversion from solid state cw lasers with small coherence time. We consider a compact and low-cost setup based on a two-crystal scheme with type-I phase matching. We reconstruct the full density matrix by quantum tomography and analyze in detail the entanglement properties of the generated state as a function of the crystal's length and the coherence time of the pump. We verify the possibility to improve the visibility using a purification protocol based on a compensation crystal.
authors.affiliation: Instituto Nazionale di Fisica Nucleare (INFN), Sezione di Milano, via Celoria 16, Milano I-20133, Italy. simone.cialdi@mi.infn.it
authors.forename: Simone
authors.initials: S
authors.lastname: Cialdi
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Castelli
authors.forename: Ilario
authors.initials: I
authors.lastname: Boscolo
authors.forename: Matteo G
authors.initials: MG
authors.lastname: Paris