Optimizing type-I polarization-entangled photons

Abstract

Optical quantum information processing needs ultra-bright sources of entangled photons, especially from synchronizable femtosecond lasers and low-cost cw-diode lasers. Decoherence due to timing information and spatial mode-dependent phase has traditionally limited the brightness of such sources. We report on a variety of methods to optimize type-I polarization-entangled sources - the combined use of different compensation techniques to engineer high-fidelity pulsed and cw-diode laser-pumped sources, as well as the first production of polarization-entanglement directly from the highly nonlinear biaxial crystal BiB3O6 (BiBO). Using spatial compensation, we show more than a 400-fold improvement in the phase flatness, which otherwise limits efficient collection of entangled photons from BiBO, and report the highest fidelity to date (99%) of any ultrafast polarization-entanglement source. Our numerical code, available on our website, can design optimal compensation crystals and simulate entanglement from a variety of type-I phasematched nonlinear crystals.

14 pages, 5 figures, 1 Table

References in corpus (5)

• Experimental entanglement of six photons in graph states
• Shaping the waveform of entangled photons
• A pulsed Sagnac source of narrowband polarization-entangled photons
• Collinear source of polarization-entangled photon pairs at non-degenerate wavelengths
• Optimal Generation of Pulsed Entangled Photon Pairs

Cited by in corpus (2)

• Generation of broadband spontaneous parametric fluorescence using multiple bulk nonlinear crystals
• Decoherence-free measurements in steering tasks