Related papers: Generation of spatially pure photon pairs in a mul…
We demonstrate a technique that generates frequency-entangled photon pairs with high polarization definition by using a single-period nonlinear crystal and single pass configuration. The technique is based on the simultaneous occurrence of…
In this work, we present a theoretical and experimental study about the spatial correlations of paired photons generated by type-II spontaneous parametric down-conversion. In particular, we show how these correlations can be positive or…
The temperature dependence of the refractive indices of potassium titanyl phosphate (KTP) are shown to enable quasi-phasematched type II spontaneous parametric downconversion (SPDC) with low temperature sensitivity. Calculations show the…
We examine the modal, spectral, and polarization entanglement properties of photon pairs generated in a nonlinear, periodically poled, two-mode waveguide (1-D planar or 2-D circular) via nondegenerate spontaneous parametric down-conversion.…
We report, for the first time, the generation of entangled photon pairs via type-0 spontaneous parametric down conversion in an ultra-thin wafer of lithium niobate in which momentum between the pump photon and daughter photons is not…
Photon-pair sources are useful for entanglement distribution. The most mature of these are spontaneous parametric downconversion (SPDC) sources, most of which achieve phasematching via engineering the domains in poled crystals or the angle…
We analyze the process of photon-pair generation via spontaneous parametric down-conversion in a quadratic nonlinear asymmetric waveguide coupler. The two waveguides have different geometry, such that light coupling only occurs within a…
We present a simple but highly efficient source of polarization-entangled photons based on spontaneous parametric down-conversion (SPDC) in bulk periodically poled potassium titanyl phosphate crystals (PPKTP) pumped by a 405 nm laser diode.…
We present an integrated source of polarization entangled photon pairs in the telecom regime, which is based on type II-phasematched parametric down-conversion (PDC) in a Ti-indiffused waveguide in periodically poled lithium niobate. The…
We present a detailed account of the two-photon states generated by SPDC in both type I and type II phase matching, including the effects of anisotropy of the nonlinear medium and the frequency spread of the down-converted fields. Accurate…
Harnessing high-dimensional entangled states of light presents a frontier for advancing quantum information technologies, from fundamental tests of quantum mechanics to enhanced computation and communication protocols. In this context, the…
Nonlinear metasurfaces have recently been established as a new platform for generating photon pairs via spontaneous parametric down-conversion. While for classical harmonic generation in metasurfaces a high level of control over all degrees…
In this work we study the transverse spatial correlation of the pair of photons generated via the process of spontaneous parametric frequency down-conversion, in periodically poled non-linear crystals illuminated by a pulsed laser beam. It…
We demonstrate a compact, robust, and highly efficient source of polarization-entangled photons, based on linear bi-directional down-conversion in a novel 'folded sandwich' configuration. Bi-directionally pumping a single periodically poled…
In this paper, we analyze spontaneous parametric down conversion in a 2D slant strip type periodically poled planar waveguide and show that such a configuration has efficiencies higher than in the case of bulk crystals with the possibility…
Two-photon state with spatial entanglement is an essential resource for testing fundamental laws of quantum mechanics and various quantum applications. Its creation typically relies on spontaneous parametric down-conversion in bulky…
We demonstrate a polarization-entangled photon-pair source obtained via a type-II non-collinear quasi-phase-matched spontaneous parametric down-conversion process with a 10-mm periodically poled KTiOPO$_4$ crystal, which is as stable and…
In this paper, we address the generation of a two-pair frequency entangled state using type-0 spontaneous parametric down-conversion process in a dual periodically poled lithium niobate waveguide. We show that, by suitable domain…
Periodically-tapered-waveguides technique is an emerging potential route to establish quasi-phase-matching schemes for efficient on-demand parametric interactions in third-order nonlinear materials. In this paper, I investigate this method…
We demonstrate a new class of frequency-entangled states generated via spontaneous parametric down-conversion under extended phase matching conditions. Biphoton entanglement with coincident signal and idler frequencies is observed over a…