@article{44081,
author = {{Serino, Laura and Gil López, Jano and Stefszky, Michael and Ricken, Raimund and Eigner, Christof and Brecht, Benjamin and Silberhorn, Christine}},
issn = {{2691-3399}},
journal = {{PRX Quantum}},
keywords = {{General Physics and Astronomy, Mathematical Physics, Applied Mathematics, Electronic, Optical and Magnetic Materials, Electrical and Electronic Engineering, General Computer Science}},
number = {{2}},
publisher = {{American Physical Society (APS)}},
title = {{{Realization of a Multi-Output Quantum Pulse Gate for Decoding High-Dimensional Temporal Modes of Single-Photon States}}},
doi = {{10.1103/prxquantum.4.020306}},
volume = {{4}},
year = {{2023}},
}
@article{30342,
author = {{Lange, Nina Amelie and Höpker, Jan Philipp and Ricken, Raimund and Quiring, Viktor and Eigner, Christof and Silberhorn, Christine and Bartley, Tim}},
issn = {{2334-2536}},
journal = {{Optica}},
keywords = {{Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials}},
number = {{1}},
publisher = {{The Optical Society}},
title = {{{Cryogenic integrated spontaneous parametric down-conversion}}},
doi = {{10.1364/optica.445576}},
volume = {{9}},
year = {{2022}},
}
@article{33672,
abstract = {{Abstract
Lithium niobate is a promising platform for integrated quantum optics. In this platform, we aim to efficiently manipulate and detect quantum states by combining superconducting single photon detectors and modulators. The cryogenic operation of a superconducting single photon detector dictates the optimisation of the electro-optic modulators under the same operating conditions. To that end, we characterise a phase modulator, directional coupler, and polarisation converter at both ambient and cryogenic temperatures. The operation voltage
V
π
/
2
of these modulators increases, due to the decrease in the electro-optic effect, by 74% for the phase modulator, 84% for the directional coupler and 35% for the polarisation converter below 8.5
K
. The phase modulator preserves its broadband nature and modulates light in the characterised wavelength range. The unbiased bar state of the directional coupler changed by a wavelength shift of 85
n
m
while cooling the device down to 5
K
. The polarisation converter uses periodic poling to phasematch the two orthogonal polarisations. The phasematched wavelength of the utilised poling changes by 112
n
m
when cooling to 5
K
.}},
author = {{Thiele, Frederik and vom Bruch, Felix and Brockmeier, Julian and Protte, Maximilian and Hummel, Thomas and Ricken, Raimund and Quiring, Viktor and Lengeling, Sebastian and Herrmann, Harald and Eigner, Christof and Silberhorn, Christine and Bartley, Tim}},
issn = {{2515-7647}},
journal = {{Journal of Physics: Photonics}},
keywords = {{Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials}},
number = {{3}},
publisher = {{IOP Publishing}},
title = {{{Cryogenic electro-optic modulation in titanium in-diffused lithium niobate waveguides}}},
doi = {{10.1088/2515-7647/ac6c63}},
volume = {{4}},
year = {{2022}},
}
@article{31329,
abstract = {{Highly directive antennas with the ability of shaping radiation patterns in desired directions are essential for efficient on-chip optical communication with reduced cross talk. In this paper, we design and optimize three distinct broadband traveling-wave tantalum pentoxide antennas exhibiting highly directional characteristics. Our antennas contain a director and reflector deposited on a glass substrate, which are excited by a dipole emitter placed in the feed gap between the two elements. Full-wave simulations in conjunction with global optimization provide structures with an enhanced linear directivity as high as 119 radiating in the substrate. The high directivity is a result of the interplay between two dominant TE modes and the leaky modes present in the antenna director. Furthermore, these low-loss dielectric antennas exhibit a near-unity radiation efficiency at the operational wavelength of 780 nm and maintain a broad bandwidth. Our numerical results are in good agreement with experimental measurements from the optimized antennas fabricated using a two-step electron-beam lithography, revealing the highly directive nature of our structures. We envision that our antenna designs can be conveniently adapted to other dielectric materials and prove instrumental for inter-chip optical communications and other on-chip applications.}},
author = {{Farheen, Henna and Yan, Lok-Yee and Quiring, Viktor and Eigner, Christof and Zentgraf, Thomas and Linden, Stefan and Förstner, Jens and Myroshnychenko, Viktor}},
issn = {{1094-4087}},
journal = {{Optics Express}},
keywords = {{tet_topic_opticalantenna}},
number = {{11}},
pages = {{19288}},
publisher = {{Optica Publishing Group}},
title = {{{Broadband optical Ta2O5 antennas for directional emission of light}}},
doi = {{10.1364/oe.455815}},
volume = {{30}},
year = {{2022}},
}
@article{39025,
author = {{Meyer-Scott, Evan and Prasannan, Nidhin and Dhand, Ish and Eigner, Christof and Quiring, Viktor and Barkhofen, Sonja and Brecht, Benjamin and Plenio, Martin B. and Silberhorn, Christine}},
issn = {{0031-9007}},
journal = {{Physical Review Letters}},
keywords = {{General Physics and Astronomy}},
number = {{15}},
publisher = {{American Physical Society (APS)}},
title = {{{Scalable Generation of Multiphoton Entangled States by Active Feed-Forward and Multiplexing}}},
doi = {{10.1103/physrevlett.129.150501}},
volume = {{129}},
year = {{2022}},
}
@article{40273,
author = {{Meyer-Scott, Evan and Prasannan, Nidhin and Dhand, Ish and Eigner, Christof and Quiring, Viktor and Barkhofen, Sonja and Brecht, Benjamin and Plenio, Martin B. and Silberhorn, Christine}},
issn = {{0031-9007}},
journal = {{Physical Review Letters}},
keywords = {{General Physics and Astronomy}},
number = {{15}},
publisher = {{American Physical Society (APS)}},
title = {{{Scalable Generation of Multiphoton Entangled States by Active Feed-Forward and Multiplexing}}},
doi = {{10.1103/physrevlett.129.150501}},
volume = {{129}},
year = {{2022}},
}
@inproceedings{43744,
abstract = {{We demonstrate theoretically and experimentally complex correlations in the photon numbers of two-mode quantum states using measurement-induced nonlinearity. For this, we combine the interference of coherent states and single photons with photon sub-traction.}},
author = {{Meier, Torsten and Hoepker, Jan Philipp and Protte, Maximilian and Eigner, Christof and Silberhorn, Christine and Sharapova, Polina R. and Sperling, Jan and Bartley, Tim}},
booktitle = {{Conference on Lasers and Electro-Optics: Applications and Technology}},
isbn = {{978-1-957171-05-0}},
location = {{San Jose, California United States}},
pages = {{JTu3A. 17}},
publisher = {{Optica Publishing Group}},
title = {{{Two-Mode Photon-Number Correlations Created by Measurement-Induced Nonlinearity}}},
doi = {{10.1364/CLEO_AT.2022.JTu3A.17}},
year = {{2022}},
}
@article{33484,
abstract = {{We study the DC conductivity in potassium titanyl phosphate (KTiOPO4, KTP) and its isomorphs KTiOAsO4 (KTA) and Rb1%K99%TiOPO4 (RKTP) and introduce a method by which to reduce the overall ionic conductivity in KTP by a potassium nitrate treatment. Furthermore, we create so-called gray tracking in KTP and investigate the ionic conductivity in theses areas. A local unintended reduction of the ionic conductivity is observed in the gray-tracked regions, which also induce additional optical absorption in the material. We show that a thermal treatment in an oxygen-rich atmosphere removes the gray tracking and brings the ionic conductivity as well as the optical transmission back to the original level. These studies can help to choose the best material and treatment for specific applications.}},
author = {{Padberg, Laura and Quiring, Viktor and Bocchini, Adriana and Santandrea, Matteo and Gerstmann, Uwe and Schmidt, Wolf Gero and Silberhorn, Christine and Eigner, Christof}},
issn = {{2073-4352}},
journal = {{Crystals}},
pages = {{1359}},
title = {{{DC Ionic Conductivity in KTP and Its Isomorphs: Properties, Methods for Suppression, and Its Connection to Gray Tracking}}},
doi = {{10.3390/cryst12101359}},
volume = {{12}},
year = {{2022}},
}
@article{23728,
abstract = {{We demonstrate the integration of amorphous tungsten silicide superconducting nanowire single-photon detectors on titanium in-diffused lithium niobate waveguides. We show proof-of-principle detection of evanescently coupled photons of 1550 nm wavelength using bidirectional waveguide coupling for two orthogonal polarization directions. We investigate the internal detection efficiency as well as detector absorption using coupling-independent characterization measurements. Furthermore, we describe strategies to improve the yield and efficiency of these devices.}},
author = {{Höpker, Jan Philipp and Verma, Varun B and Protte, Maximilian and Ricken, Raimund and Quiring, Viktor and Eigner, Christof and Ebers, Lena and Hammer, Manfred and Förstner, Jens and Silberhorn, Christine and Mirin, Richard P and Woo Nam, Sae and Bartley, Tim}},
issn = {{2515-7647}},
journal = {{Journal of Physics: Photonics}},
pages = {{034022}},
title = {{{Integrated superconducting nanowire single-photon detectors on titanium in-diffused lithium niobate waveguides}}},
doi = {{10.1088/2515-7647/ac105b}},
volume = {{3}},
year = {{2021}},
}
@article{26221,
author = {{Bartnick, Moritz and Santandrea, Matteo and Höpker, Jan Philipp and Thiele, Frederik and Ricken, Raimund and Quiring, Viktor and Eigner, Christof and Herrmann, Harald and Silberhorn, Christine and Bartley, Tim}},
issn = {{2331-7019}},
journal = {{Physical Review Applied}},
title = {{{Cryogenic Second-Harmonic Generation in Periodically Poled Lithium Niobate Waveguides}}},
doi = {{10.1103/physrevapplied.15.024028}},
year = {{2021}},
}
@article{23826,
abstract = {{Potassium titanyl phosphate (KTP) is a nonlinear optical material with applications in high-power frequency conversion or quasi-phase matching in submicron period domain grids. A prerequisite for these applications is a precise control and understanding of the poling mechanisms to enable the fabrication of high-grade domain grids. In contrast to the widely used material lithium niobate, the domain growth in KTP is less studied, because many standard methods, such as selective etching or polarization microscopy, provides less insight or are not applicable on non-polar surfaces, respectively. In this work, we present results of confocal Raman-spectroscopy of the ferroelectric domain structure in KTP. This analytical method allows for the visualization of domain grids of the non-polar KTP y-face and therefore more insight into the domain-growth and -structure in KTP, which can be used for improved domain fabrication.}},
author = {{Brockmeier, Julian and Mackwitz, Peter Walter Martin and Rüsing, Michael and Eigner, Christof and Padberg, Laura and Santandrea, Matteo and Silberhorn, Christine and Zrenner, Artur and Berth, Gerhard}},
issn = {{2073-4352}},
journal = {{Crystals}},
title = {{{Non-Invasive Visualization of Ferroelectric Domain Structures on the Non-Polar y-Surface of KTiOPO4 via Raman Imaging}}},
doi = {{10.3390/cryst11091086}},
year = {{2021}},
}
@misc{38135,
author = {{Padberg, Laura and Eigner, Christof and Santandrea, Matteo and Silberhorn, Christine}},
title = {{{Production of waveguides made of materials from the KTP family}}},
year = {{2021}},
}
@article{22770,
author = {{Gil López, Jano and Santandrea, Matteo and Roland, Ganaël and Brecht, Benjamin and Eigner, Christof and Ricken, Raimund and Quiring, Viktor and Silberhorn, Christine}},
issn = {{1367-2630}},
journal = {{New Journal of Physics}},
title = {{{Improved non-linear devices for quantum applications}}},
doi = {{10.1088/1367-2630/ac09fd}},
year = {{2021}},
}
@article{21022,
author = {{Allgaier, M. and Ansari, V. and Donohue, J. M. and Eigner, Christof and Quiring, V. and Ricken, R. and Brecht, Benjamin and Silberhorn, Christine}},
issn = {{2469-9926}},
journal = {{Physical Review A}},
title = {{{Pulse shaping using dispersion-engineered difference frequency generation}}},
doi = {{10.1103/physreva.101.043819}},
volume = {{101}},
year = {{2020}},
}
@article{22771,
author = {{Stefszky, Michael and Santandrea, Matteo and vom Bruch, Felix and Krapick, S. and Eigner, Christof and Ricken, R. and Quiring, V. and Herrmann, Harald and Silberhorn, Christine}},
issn = {{1094-4087}},
journal = {{Optics Express}},
title = {{{Waveguide resonator with an integrated phase modulator for second harmonic generation}}},
doi = {{10.1364/oe.412824}},
year = {{2020}},
}
@article{20157,
author = {{Thiele, Frederik and vom Bruch, Felix and Quiring, Victor and Ricken, Raimund and Herrmann, Harald and Eigner, Christof and Silberhorn, Christine and Bartley, Tim}},
issn = {{1094-4087}},
journal = {{Optics Express}},
title = {{{Cryogenic electro-optic polarisation conversion in titanium in-diffused lithium niobate waveguides}}},
doi = {{10.1364/oe.399818}},
year = {{2020}},
}
@article{25920,
author = {{Padberg, Laura and Santandrea, Matteo and Rüsing, Michael and Brockmeier, Julian and Mackwitz, Peter and Berth, Gerhard and Zrenner, Artur and Eigner, Christof and Silberhorn, Christine}},
issn = {{1094-4087}},
journal = {{Optics Express}},
title = {{{Characterisation of width-dependent diffusion dynamics in rubidium-exchanged KTP waveguides}}},
doi = {{10.1364/oe.397074}},
year = {{2020}},
}
@article{21025,
author = {{Eigner, Christof and Padberg, Laura and Santandrea, Matteo and Herrmann, Harald and Brecht, Benjamin and Silberhorn, Christine}},
issn = {{1094-4087}},
journal = {{Optics Express}},
number = {{22}},
title = {{{Spatially single mode photon pair source at 800 nm in periodically poled Rubidium exchanged KTP waveguides}}},
doi = {{10.1364/oe.399483}},
volume = {{28}},
year = {{2020}},
}
@article{19190,
abstract = {{Polarons in dielectric crystals play a crucial role for applications in integrated electronics and optoelectronics. In this work, we use density-functional theory and Green's function methods to explore the microscopic structure and spectroscopic signatures of electron polarons in lithium niobate (LiNbO3). Total-energy calculations and the comparison of calculated electron paramagnetic resonance data with available measurements reveal the formation of bound
polarons at Nb_Li antisite defects with a quasi-Jahn-Teller distorted, tilted configuration. The defect-formation energies further indicate that (bi)polarons may form not only at
Nb_Li antisites but also at structures where the antisite Nb atom moves into a neighboring empty oxygen octahedron. Based on these structure models, and on the calculated charge-transition levels and potential-energy barriers, we propose two mechanisms for the optical and thermal splitting of bipolarons, which provide a natural explanation for the reported two-path recombination of bipolarons. Optical-response calculations based on the Bethe-Salpeter equation, in combination with available experimental data and new measurements of the optical absorption spectrum, further corroborate the geometries proposed here for free and defect-bound (bi)polarons.}},
author = {{Schmidt, Falko and Kozub, Agnieszka L. and Biktagirov, Timur and Eigner, Christof and Silberhorn, Christine and Schindlmayr, Arno and Schmidt, Wolf Gero and Gerstmann, Uwe}},
issn = {{2643-1564}},
journal = {{Physical Review Research}},
number = {{4}},
publisher = {{American Physical Society}},
title = {{{Free and defect-bound (bi)polarons in LiNbO3: Atomic structure and spectroscopic signatures from ab initio calculations}}},
doi = {{10.1103/PhysRevResearch.2.043002}},
volume = {{2}},
year = {{2020}},
}
@article{20682,
author = {{Bocchini, Adriana and Eigner, Christof and Silberhorn, Christine and Schmidt, Wolf Gero and Gerstmann, Uwe}},
journal = {{Phys. Rev. Materials}},
pages = {{124402}},
publisher = {{American Physical Society}},
title = {{{Understanding gray track formation in KTP: Ti^3+ centers studied from first principles}}},
doi = {{10.1103/PhysRevMaterials.4.124402}},
volume = {{4}},
year = {{2020}},
}