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Jan Perina Jr

Publications and source records attributed to Jan Perina Jr.

43 records · Page 3Linked to original sources
arXiv2007

Antisymmetric entangled two-photon states generated in nonlinear GaN/AlN photonic-band-gap structures

The properties of an entangled two-photon state antisymmetric in frequencies are studied. At a beam-splitter, two entangled photons are perfectly anti-correlated. In addition, they cannot be detected at the same time instant despite the fact that their detection times are confined to a narrow time window, i.e. they are temporally anti-bunched. Using nonlinear photonic-band-gap structures made of GaN/AlN, two schemes for generating such states are described.

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arXiv2007

Squeezed-light generation in a nonlinear planar waveguide with a periodic corrugation

Two-mode nonlinear interaction (second-harmonic and second-subharmonic generation) in a planar waveguide with a small periodic corrugation at the surface is studied. Scattering of the interacting fields on the corrugation leads to constructive interference that enhances the nonlinear process provided that all the interactions are phase matched. Conditions for the overall phase matching are found. Compared with a perfectly quasi-phase-matched waveguide, better values of squeezing as well as higher intensities are reached under these conditions. Procedure for finding optimum values of parameters for squeezed-light generation is described.

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arXiv2007

Experimental joint signal-idler quasi-distributions and photon-number statistics for mesoscopic twin beams

Joint signal-idler photoelectron distributions of twin beams containing several tens of photons per mode have been measured recently. Exploiting a microscopic quantum theory for joint quasi-distributions in parametric down-conversion developed earlier we characterize properties of twin beams in terms of quasi-distributions using experimental data. Negative values as well as oscillating behaviour in quantum region are characteristic for the subsequently determined joint signal-idler quasi-distributions of integrated intensities. Also the conditional and difference photon-number distributions are shown to be sub-Poissonian and sub-shot-noise, respectively.

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arXiv2003

Experimental verification of energy correlations in entangled photon pairs

Properties of entangled photon pairs generated in spontaneous parametric down-conversion are investigated in interference experiments. Strong energy correlations are demonstrated in a direct way. If a signal photon is detected behind a narrow spectral filter, then interference appears in the Mach-Zehnder interferometer placed in the route of the idler photon, even if the path difference in the interferometer exceeds the coherence length of the light. Narrow time correlations of the detection instants are demonstrated for the same photon-pair source using the Hong-Ou-Mandel interferometer. Both these two effects may be exhibited only by an entangled state.

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arXiv2001

Quantum cryptography using photon source based on postselection from entangled two-photon states

A photon source based on postselection from entangled photon pairs produced by parametric frequency down-conversion is suggested. Its ability to provide good approximations of single-photon states is examined. Application of this source in quantum cryptography for quantum key distribution is discussed. Advantages of the source compared to other currently used sources are clarified. Future prospects of the photon source are outlined.

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arXiv1999

Properties of pulsed entangled two-photon fields

The dependence of one- and two-photon characteristics of pulsed entangled two-photon fields generated in spontaneous parametric down-conversion on the pump-pulse properties (shape of the pump-pulse spectrum and its internal structure) is examined. It is shown that entangled two-photon fields with defined properties can be generated. A general relation between the spectra of the down-converted fields is established. As a special case interference of two partially overlapping pulsed two-photon fields is studied. Fourth-order interference pattern of entangled two-photon fields is investigated in the polarization analog of the Hong-Ou-Mandel interferometer.

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