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Pulsed parametric downconversion (PDC) processes generate photon pairs with a rich spectral-temporal structure, which offer an attractive potential for quantum information and communication applications. In this paper, we investigate the…

Quantum Physics · Physics 2013-06-21 Benjamin Brecht , Christine Silberhorn

We present a pulsed and integrated, highly non-degenerate parametric downconversion (PDC) source of heralded single photons at telecom wavelengths, paired with heralding photons around 800 nm. The active PDC section is combined with a…

We investigate entangled Schr\"odinger cat-like states (SCLSs) in degenerate and non-degenerate spontaneous parametric down-conversion (SPDC) with a fully quantized, depleted pump. Our fully quantum treatment, visualized via Wigner…

Quantum Physics · Physics 2026-04-03 Ranjit Singh , Alexander E. Teretenkov

We demonstrate an experimental protocol for the preparation and control of heralded single photons in inhomogeneously polarized states, such as Vector Vortex and Full Poincar\'e beam states. A laser beam is shaped by a voltage-controlled…

State-of-the-art photon sources based on spontaneous parametric down-conversion (SPDC) currently rely on artificial structuring of the material nonlinearity to satisfy phase-matching conditions. This technique, known as periodic poling, is…

Optics · Physics 2026-04-21 Tim F. Weiss , Hamed Arianfard , Yang Yang , Alberto Peruzzo

We describe a cavity-enhanced spontaneous parametric down-conversion (CE-SPDC) source for narrowband photon pairs with filters such that over 97% of the correlated photons are in a single mode of 4.3(4) MHz bandwidth. Type-II phase…

A method is proposed for generating and discriminating Bell states of high fidelity from consecutive single-photons generated in a semiconductor quantum dot. The use of a non-symmetric beam splitter is found to be essential and sufficient,…

Quantum Physics · Physics 2012-09-17 Partha Ghose

We demonstrate experimentally a new technique to control the bandwidth and the type of frequency correlations (correlation, anticorrelation, and even uncorrelation) of entangled photons generated by spontaneous parametric downconversion.…

Quantum Physics · Physics 2009-11-13 M. Hendrych , M. Micuda , J. P. Torres

Double-pair emission from type-II parametric down conversion results in a highly entangled 4-photon state. Due to interference, which is similar to bunching from thermal emission, this state is not simply a product of two pairs. The…

Quantum Physics · Physics 2009-11-07 Harald Weinfurter , Marek Zukowski

We use polarization-entangled photon pairs to demonstrate quantum nonlocality in an experiment suitable for advanced undergraduates. The photons are produced by spontaneous parametric downconversion using a violet diode laser and two…

Quantum Physics · Physics 2009-11-07 Dietrich Dehlinger , M. W. Mitchell

We consider the formation of cold ground-state polar molecules in a low vibrational level by laser fields. Starting from a pair of cold colliding atoms of dissimilar species, we propose a strategy consisting of three steps. In the first…

Atomic Physics · Physics 2026-01-14 Emanuel F. de Lima

We present an ultrabright polarization-entangled photon source that is optimally coupled into single-mode fibers (SMFs). This study theoretically and experimentally examines the characteristics of spontaneous parametric down-conversion…

Quantum Physics · Physics 2024-09-25 Kyungdeuk Park , Jungmo Lee , Dong-Gil Im , Dongkyu Kim , Yong Sup Ihn

Generation and characterization of entanglement are crucial tasks in quantum information processing. A hypothesis testing scheme for entanglement has been formulated. Three designs were proposed to test the entangled photon states created…

We report on the generation of an indistinguishable heralded single-photon state, using highly nondegenerate spontaneous parametric downconversion (SPDC). Spectrally factorable photon pairs can be generated by incorporating a broadband pump…

Quantum Physics · Physics 2016-05-11 Fumihiro Kaneda , Karina Garay-Palmett , Alfred B. U'Ren , Paul G. Kwiat

We report on theoretical and experimental demonstration of high-efficiency coupling of two-photon entangled states produced in the nonlinear process of spontaneous parametric down conversion into a single-mode fiber. We determine…

Quantum Physics · Physics 2015-06-26 F. A. Bovino , P. Varisco , A. M. Colla , G. Castagnoli , G. Di Giuseppe , A. V. Sergienko

We report on an experiment demonstrating entanglement swapping of time-frequency entangled photons. We perform a frequency-resolved Bell-state measurement on the idler photons from two independent entangled photon pairs, which projects the…

Quantum Physics · Physics 2019-10-16 Sofiane Merkouche , Valérian Thiel , Alex O. C. Davis , Brian J. Smith

A simple experimental setup consisting of a spontaneous parametric down-conversion source and passive linear optics is proposed for conditional preparation of a maximally entangled polarization state of two photons. Successful preparation…

Quantum Physics · Physics 2009-11-07 C. Sliwa , K. Banaszek

We present the generation of approximated coherent state superpositions - referred to as Schr\"odinger cat states - by the process of subtracting single photons from picosecond pulsed squeezed states of light at 830 nm. The squeezed vacuum…

Parametric down-conversion (PDC) offers the possibility to control the fabrication of non-Gaussian states such as Fock states. However, in conventional PDC sources energy and momentum conservation introduce strict frequency and photon…

Quantum Physics · Physics 2015-05-14 K. Laiho , K. N. Cassemiro , Ch. Silberhorn

We present a source of polarization entangled photon pairs based on spontaneous parametric downconversion engineered for frequency uncorrelated telecom photon generation. Our source provides photon pairs that display, simultaneously, the…