Jirí Svozilík - Academia.edu (original) (raw)
Papers by Jirí Svozilík
Physical Review A, 2015
Linear-optical interferometers play a key role in designing circuits for quantum information proc... more Linear-optical interferometers play a key role in designing circuits for quantum information processing and quantum communications. Even though nested Mach-Zehnder interferometers appear easy to describe, there are occasions when they provide unintuitive results. This paper explains the results of a highly discussed experiment performed by Danan et al. [Phys. Rev. Lett. 111, 240402 (2013)] using a standard approach. We provide a simple and intuitive one-state vector formalism capable of interpreting their experiment. Additionally, we cross-checked our model with a classical-physics based approach and found that both models are in complete agreement. We argue that the quantity used in the mentioned experiment is not a suitable which-path witness producing seemingly contra-intuitive results. To circumvent this issue, we establish a more reliable which-path witness and show that it yields well expected outcomes of the experiment.
We describe properties of entangled photon pairs generated by spontaneous parametric down-convers... more We describe properties of entangled photon pairs generated by spontaneous parametric down-conversion in periodically poled nonlinear crystals. These materials can serve as a useful bright source of photon pairs which properties can be tailored on demand. Especially photon pairs with broad spectra and sharp temporal features can be observed. Both uniform and chirped poling are considered. Spectral properties of the generated photons, photon fluxes, coincidence-count patterns in a Hong-Ou-Mandel interferometer, entropy of entanglement, as well as transverse profiles of intensities of the generated photon fields are discussed. Also the correlation area of two photons comprising a photon pair has been studied as it depends on parameters of periodical poling. Attention is also paid to structures with randomly distributed boundaries.
Physical Review A, 2009
Using a rigorous quantum model a comprehensive study of physical properties of entangled photon p... more Using a rigorous quantum model a comprehensive study of physical properties of entangled photon pairs generated in spontaneous parametric down-conversion in chirped periodically-poled crystals is presented. Spectral, temporal, as well as spatial characteristics of photon pairs are analyzed. Spectral bandwidths, photon-pair flux, and entanglement area can be effectively controlled by chirping. Quantification of entanglement between photons in a pair is given. Splitting of entanglement area in the transverse plane accompanied by spectral splitting has been revealed. Using the model temperature dependencies of the experimental intensity profiles reported in literature have been explained.
Physical Review A, 2011
The generation of photon pairs from randomly poled nonlinear crystals is investigated using an an... more The generation of photon pairs from randomly poled nonlinear crystals is investigated using an analytically soluble model and numerical calculations. Randomly poled crystals are discovered as sources of entangled ultra broadband signal and idler fields. Their photon-pair generation rates scale linearly with the number of domains. Entanglement times as short as several fs can be reached. A comparison with chirped periodically poled structures is given and reveals close similarity.
Optics Express, 2011
This work proposes and analyses a novel approach for the generation of separable (quantum uncorre... more This work proposes and analyses a novel approach for the generation of separable (quantum uncorrelated) photon pairs based on spontaneous parametric down-conversion in Bragg reflection waveguides composed of semiconductor AlGaN layers. This platform allows the removal of any spectral correlation between paired photons that propagate in different spatial modes. The photons can be designed to show equal or different spectra by tuning the structural parameters and hence the dispersion of the waveguide.
In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching ... more In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching the phasematching of spontaneous parametric downconversion process in semiconductor materials. We have designed two different waveguide structures. The first one is based on AlGaN and it is able to produce spectrally uncorrelated photon pairs. The second one is based on AlGaAs and it allows us to generate entangled photon pairs with ultra-broad spectra. Spontaneous-parametric-downconversion and second-harmonic-generation experiments are presented.
Nonlinear Optics and Applications III, 2009
We describe properties of entangled photon pairs generated by spontaneous parametric down-convers... more We describe properties of entangled photon pairs generated by spontaneous parametric down-conversion in periodically poled nonlinear crystals. These materials can serve as a useful bright source of photon pairs which properties can be tailored on demand. Especially photon pairs with broad spectra and sharp temporal features can be observed. Both uniform and chirped poling are considered. Spectral properties of the
Optics Express - OPT EXPRESS, 2010
Randomly poled nonlinear crystals are shown to be able to emit intense ultra-broadband photon-pai... more Randomly poled nonlinear crystals are shown to be able to emit intense ultra-broadband photon-pair fields with properties comparable to those coming from chirped periodically-poled crystals. Their intensities scale linearly with the number of domains. Also photon pairs extending over intervals with durations comparable to one optical cycle can be generated in these crystals.
Optics Express, 2011
This work proposes and analyses a novel approach for the generation of separable (quantum uncorre... more This work proposes and analyses a novel approach for the generation of separable (quantum uncorrelated) photon pairs based on spontaneous parametric down-conversion in Bragg reflection waveguides composed of semiconductor AlGaN layers. This platform allows the removal of any spectral correlation between paired photons that propagate in different spatial modes. The photons can be designed to show equal or different spectra by tuning the structural parameters and hence the dispersion of the waveguide.
Optics Express, 2013
We demonstrate experimentally that spontaneous parametric down-conversion in an Al x Ga 1−x As se... more We demonstrate experimentally that spontaneous parametric down-conversion in an Al x Ga 1−x As semiconductor Bragg reflection waveguide can make for paired photons highly entangled in the polarization degree of freedom at the telecommunication wavelength of 1550 nm. The pairs of photons show visibility higher than 90% in several polarization bases and violate a Clauser-Horne-Shimony-Holt Bell-like inequality by more than 3 standard deviations. This represents a significant step toward the realization of efficient and versatile self pumped sources of entangled photon pairs on-chip.
In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching ... more In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching the phasematching of spontaneous parametric downconversion process in semiconductor materials. We have designed two different waveguide structures. The first one is based on AlGaN and it is able to produce spectrally uncorrelated photon pairs. The second one is based on AlGaAs and it allows us to generate entangled photon pairs with ultra-broad spectra. Spontaneous-parametric-downconversion and second-harmonic-generation experiments are presented.
Optics Express, 2012
We put forward a new highly efficient source of paired photons entangled in polarization with an ... more We put forward a new highly efficient source of paired photons entangled in polarization with an ultra-large bandwidth. The photons are generated by means of a conveniently designed spontaneous parametric down-conversion process in a semiconductor type-II Bragg reflection waveguide. The proposed scheme aims at being a key element of an integrated source of polarization-entangled photon pairs highly suitable for its use in a multi-user quantum-key-distribution system.
Photon Counting Applications, Quantum Optics, and Quantum Information Transfer and Processing III, 2011
In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching ... more In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching the phasematching of spontaneous parametric downconversion process in semiconductor materials. We have designed two different waveguide structures. The first one is based on AlGaN and it is able to produce spectrally uncorrelated photon pairs. The second one is based on AlGaAs and it allows us to generate entangled photon pairs with ultra-broad spectra. Spontaneous-parametric-downconversion and second-harmonic-generation experiments are presented.
Optics Express, 2011
This work proposes and analyses a novel approach for the generation of separable (quantum uncorre... more This work proposes and analyses a novel approach for the generation of separable (quantum uncorrelated) photon pairs based on spontaneous parametric down-conversion in Bragg reflection waveguides composed of semiconductor AlGaN layers. This platform allows the removal of any spectral correlation between paired photons that propagate in different spatial modes. The photons can be designed to show equal or different spectra by tuning the structural parameters and hence the dispersion of the waveguide.
Physical Review A, 2015
Linear-optical interferometers play a key role in designing circuits for quantum information proc... more Linear-optical interferometers play a key role in designing circuits for quantum information processing and quantum communications. Even though nested Mach-Zehnder interferometers appear easy to describe, there are occasions when they provide unintuitive results. This paper explains the results of a highly discussed experiment performed by Danan et al. [Phys. Rev. Lett. 111, 240402 (2013)] using a standard approach. We provide a simple and intuitive one-state vector formalism capable of interpreting their experiment. Additionally, we cross-checked our model with a classical-physics based approach and found that both models are in complete agreement. We argue that the quantity used in the mentioned experiment is not a suitable which-path witness producing seemingly contra-intuitive results. To circumvent this issue, we establish a more reliable which-path witness and show that it yields well expected outcomes of the experiment.
We describe properties of entangled photon pairs generated by spontaneous parametric down-convers... more We describe properties of entangled photon pairs generated by spontaneous parametric down-conversion in periodically poled nonlinear crystals. These materials can serve as a useful bright source of photon pairs which properties can be tailored on demand. Especially photon pairs with broad spectra and sharp temporal features can be observed. Both uniform and chirped poling are considered. Spectral properties of the generated photons, photon fluxes, coincidence-count patterns in a Hong-Ou-Mandel interferometer, entropy of entanglement, as well as transverse profiles of intensities of the generated photon fields are discussed. Also the correlation area of two photons comprising a photon pair has been studied as it depends on parameters of periodical poling. Attention is also paid to structures with randomly distributed boundaries.
Physical Review A, 2009
Using a rigorous quantum model a comprehensive study of physical properties of entangled photon p... more Using a rigorous quantum model a comprehensive study of physical properties of entangled photon pairs generated in spontaneous parametric down-conversion in chirped periodically-poled crystals is presented. Spectral, temporal, as well as spatial characteristics of photon pairs are analyzed. Spectral bandwidths, photon-pair flux, and entanglement area can be effectively controlled by chirping. Quantification of entanglement between photons in a pair is given. Splitting of entanglement area in the transverse plane accompanied by spectral splitting has been revealed. Using the model temperature dependencies of the experimental intensity profiles reported in literature have been explained.
Physical Review A, 2011
The generation of photon pairs from randomly poled nonlinear crystals is investigated using an an... more The generation of photon pairs from randomly poled nonlinear crystals is investigated using an analytically soluble model and numerical calculations. Randomly poled crystals are discovered as sources of entangled ultra broadband signal and idler fields. Their photon-pair generation rates scale linearly with the number of domains. Entanglement times as short as several fs can be reached. A comparison with chirped periodically poled structures is given and reveals close similarity.
Optics Express, 2011
This work proposes and analyses a novel approach for the generation of separable (quantum uncorre... more This work proposes and analyses a novel approach for the generation of separable (quantum uncorrelated) photon pairs based on spontaneous parametric down-conversion in Bragg reflection waveguides composed of semiconductor AlGaN layers. This platform allows the removal of any spectral correlation between paired photons that propagate in different spatial modes. The photons can be designed to show equal or different spectra by tuning the structural parameters and hence the dispersion of the waveguide.
In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching ... more In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching the phasematching of spontaneous parametric downconversion process in semiconductor materials. We have designed two different waveguide structures. The first one is based on AlGaN and it is able to produce spectrally uncorrelated photon pairs. The second one is based on AlGaAs and it allows us to generate entangled photon pairs with ultra-broad spectra. Spontaneous-parametric-downconversion and second-harmonic-generation experiments are presented.
Nonlinear Optics and Applications III, 2009
We describe properties of entangled photon pairs generated by spontaneous parametric down-convers... more We describe properties of entangled photon pairs generated by spontaneous parametric down-conversion in periodically poled nonlinear crystals. These materials can serve as a useful bright source of photon pairs which properties can be tailored on demand. Especially photon pairs with broad spectra and sharp temporal features can be observed. Both uniform and chirped poling are considered. Spectral properties of the
Optics Express - OPT EXPRESS, 2010
Randomly poled nonlinear crystals are shown to be able to emit intense ultra-broadband photon-pai... more Randomly poled nonlinear crystals are shown to be able to emit intense ultra-broadband photon-pair fields with properties comparable to those coming from chirped periodically-poled crystals. Their intensities scale linearly with the number of domains. Also photon pairs extending over intervals with durations comparable to one optical cycle can be generated in these crystals.
Optics Express, 2011
This work proposes and analyses a novel approach for the generation of separable (quantum uncorre... more This work proposes and analyses a novel approach for the generation of separable (quantum uncorrelated) photon pairs based on spontaneous parametric down-conversion in Bragg reflection waveguides composed of semiconductor AlGaN layers. This platform allows the removal of any spectral correlation between paired photons that propagate in different spatial modes. The photons can be designed to show equal or different spectra by tuning the structural parameters and hence the dispersion of the waveguide.
Optics Express, 2013
We demonstrate experimentally that spontaneous parametric down-conversion in an Al x Ga 1−x As se... more We demonstrate experimentally that spontaneous parametric down-conversion in an Al x Ga 1−x As semiconductor Bragg reflection waveguide can make for paired photons highly entangled in the polarization degree of freedom at the telecommunication wavelength of 1550 nm. The pairs of photons show visibility higher than 90% in several polarization bases and violate a Clauser-Horne-Shimony-Holt Bell-like inequality by more than 3 standard deviations. This represents a significant step toward the realization of efficient and versatile self pumped sources of entangled photon pairs on-chip.
In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching ... more In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching the phasematching of spontaneous parametric downconversion process in semiconductor materials. We have designed two different waveguide structures. The first one is based on AlGaN and it is able to produce spectrally uncorrelated photon pairs. The second one is based on AlGaAs and it allows us to generate entangled photon pairs with ultra-broad spectra. Spontaneous-parametric-downconversion and second-harmonic-generation experiments are presented.
Optics Express, 2012
We put forward a new highly efficient source of paired photons entangled in polarization with an ... more We put forward a new highly efficient source of paired photons entangled in polarization with an ultra-large bandwidth. The photons are generated by means of a conveniently designed spontaneous parametric down-conversion process in a semiconductor type-II Bragg reflection waveguide. The proposed scheme aims at being a key element of an integrated source of polarization-entangled photon pairs highly suitable for its use in a multi-user quantum-key-distribution system.
Photon Counting Applications, Quantum Optics, and Quantum Information Transfer and Processing III, 2011
In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching ... more In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching the phasematching of spontaneous parametric downconversion process in semiconductor materials. We have designed two different waveguide structures. The first one is based on AlGaN and it is able to produce spectrally uncorrelated photon pairs. The second one is based on AlGaAs and it allows us to generate entangled photon pairs with ultra-broad spectra. Spontaneous-parametric-downconversion and second-harmonic-generation experiments are presented.
Optics Express, 2011
This work proposes and analyses a novel approach for the generation of separable (quantum uncorre... more This work proposes and analyses a novel approach for the generation of separable (quantum uncorrelated) photon pairs based on spontaneous parametric down-conversion in Bragg reflection waveguides composed of semiconductor AlGaN layers. This platform allows the removal of any spectral correlation between paired photons that propagate in different spatial modes. The photons can be designed to show equal or different spectra by tuning the structural parameters and hence the dispersion of the waveguide.