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.
© 2008 Optical Society of America
Original Manuscript: November 12, 2007
Revised Manuscript: January 17, 2008
Manuscript Accepted: January 18, 2008
Published: April 8, 2008
Simone Cialdi, Fabrizio Castelli, Ilario Boscolo, and Matteo G. Paris, "Generation of entangled photon pairs using small-coherence-time continuous wave pump lasers," Appl. Opt. 47, 1832-1836 (2008)