Properties of entangled photon pairs generated by a CW laser with small coherence time: theory and experiment

Abstract

The generation of entangled photon pairs by parametric down--conversion from solid state CW lasers with small coherence time is theoretically and experimentally analyzed. We consider a compact and low-cost setup based on a two-crystal scheme with Type-I phase matching. We study the effect of the pump coherence time over the entangled state visibility and over the violation of Bell's inequality, as a function of the crystals length. The full density matrix is reconstructed by quantum tomography. The proposed theoretical model is verified using a purification protocol based on a compensation crystal.

arXiv comment10 pages, 11 figures

References in corpus (11)

• Entanglement of a Pair of Quantum Bits
• On the Measurement of Qubits
• Ultra-bright source of polarization-entangled photons
• Experimental Quantum State Tomography of Optical Fields and Ultrafast Statistical Sampling
• Unknown Quantum States and Operations, a Bayesian View
• Research on Hidden Variable Theories: a review of recent progresses
• Entangled photons, nonlocality and Bell inequalities in the undergraduate laboratory
• Generation of polarization-entangled photon pairs in a cascade of two type-I crystals pumped by femtosecond pulses
• Quorum of observables for universal quantum estimation
• Validity of Rate Equations for Zeeman Coherences for Analysis of Nonlinear Interaction of Atoms with Laser Radiation
• Generation of different Bell states within the SPDC phase-matching bandwidth

Cited by in corpus (11)

• Experimental investigation of initial system-environment correlations via trace distance evolution
• Statistical estimation of the quality of quantum-tomography protocols
• Experimental estimation of quantum discord for polarization qubit and the use of fidelity to assess quantum correlations
• Assessing the significance of fidelity as a figure of merit in quantum state reconstruction of discrete and continuous variable systems
• Programmable entanglement oscillations in a non Markovian channel
• Quantum probes to assess correlations in a composite system
• Counting of Hong-Ou-Mandel Bunched Optical Photons Using a Fast Pixel Camera
• Demonstration of a programmable source of two-photon multiqubit entangled states
• Programmable purification of type-I polarization-entanglement
• Effect of incoherent pump on two-mode entanglement in optical parametric generation
• Nonlocal compensation of pure phase objects with entangled photons