Related papers: Broadband Spontaneous Parametric Downconversion in…
Second harmonic generation in thin film periodically poled lithium niobate (PPLN) is constrained by an efficiency-bandwidth trade-off and fabrication-sensitive scaling. We demonstrate a racetrack resonator incorporating a short PPLN section…
We study the joint spectral properties of photon pairs generated by spontaneous parametric down-conversion in a one-dimensional nonlinear photonic crystal in a collinear, degenerate, type-II geometry. We show that the photonic crystal…
High dimensional quantum states are of fundamental interest for quantum information processing. They give access to large Hilbert spaces and, in turn, enable the encoding of quantum information on multiple modes. One method to create such…
Entangled photon pairs are crucial resources for quantum information processing protocols. Via the process of spontaneous parametric down-conversion (SPDC), we can generate these photon pairs using bulk nonlinear crystals. Traditionally,…
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.…
One-photon and two-photon wavepackets of entangled two-photon states in spontaneous parametric down-conversion (SPDC) fields are calculated and measured experimentally. For type-II SPDC, measured one-photon and two-photon wavepackets agree…
High efficiency, sub-MHz bandwidth photon pair generators will enable the field of quantum technology to transition from laboratory demonstrations to transformational applications involving information transfer from photons to atoms. While…
Sources of entangled photon pairs are a key component in both fundamental tests of quantum theory and practical applications such as quantum key distribution and quantum computing. In this work, we describe and characterize a source of…
Coherence properties of the down-converted beams generated in spontaneous parametric down-conversion are investigated in detail using an iCCD camera. Experimental results are compared with those from a theoretical model developed for pulsed…
We experimentally demonstrate a violation of local realism with highly spatially multimode polarization-entangled two-photon states produced by spontaneous parametric down-conversion (SPDC) pumped by a spatially incoherent light source-a…
Here we demonstrate the efficient photon-pair generation via spontaneous parametric down conversion from a semiconductor metasurface supporting dual quasi-bound states in the continuum (quasi-BICs). In a simple metasurface design composed…
With the assistance of a single cyclic three-level system, which can be realized by a superconducting flux qubit, we study theoretically the degenerate microwave parametric down-conversion (PDC) in a superconducting transmission line…
We study the effect of degenerate parametric down-conversion (DPDC) in an ensemble of two-level quantum emitters (QEs) coupled via near-field interactions to a single surface plasmon (SP) mode of a nonlinear plasmonic cavity. For this…
We report the efficient generation of high-gain parametric down-conversion, including pump depletion, with pump powers as low as 100 $\mu$W (energies $0.1$~$\mu$J/pulse) and conversion efficiencies up to 33\%. In our simple configuration,…
We describe a new scheme to fully control the joint spectrum of paired photons generated in spontaneous parametric down-conversion. We show the capability of this method to generate frequency-uncorrelated photon pairs that are pure and…
We analyze the process of simultaneous photon pair generation and quantum walks realized by spontaneous parametric down conversion of a pump beam in a quadratic nonlinear waveguide array. We demonstrate that this flexible platform allows…
We study the spectral properties of Spontaneous Parametric Down Conversion in a periodically poled waveguided structure of KTP crystal pumped by ultra-short pulses. Our theoretical analysis reveals a strongly multimode and asymmetric…
We explore the consequences of varying the pump beam waist that illuminates a nonlinear crystal, realizing spontaneous parametric down-conversion (SPDC). The coherence is transferred from the marginal one-photon wavefunction to the…
High flux of hyperentangled photons entails collecting the two-photon emission over relatively wide extent in frequency and transverse space within which the photon pairs are simultaneously entangled in multiple degrees of freedom. In this…
Optimizing the brightness of a spontaneous parametric down conversion (SPDC) source is an important task for many quantum information applications. We investigate the optimal focusing conditions to maximize the number of photons produced in…