@article{61252,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>The biexciton‐exciton emission cascade commonly used in quantum‐dot systems to generate polarization entanglement yields photons with intrinsically limited indistinguishability. In the present work, it focuses on the generation of pairs of photons with high degrees of polarization entanglement and simultaneously high indistinguishability. It achieves this goal by selectively reducing the biexciton lifetime with an optical resonator. It demonstrates that a suitably tailored circular Bragg reflector fulfills the requirements of sufficient selective Purcell enhancement of biexciton emission paired with spectrally broad photon extraction and twofold degenerate optical modes. The in‐depth theoretical study combines (i) the optimization of realistic photonic structures solving Maxwell's equations from which model parameters are extracted as input for (ii) microscopic simulations of quantum‐dot cavity excitation dynamics with full access to photon properties. It reports non‐trivial dependencies on system parameters and use the predictive power of the combined theoretical approach to determine the optimal range of Purcell enhancement that maximizes indistinguishability and entanglement to near unity values, here specifically for the telecom C‐band at 1550 nm.</jats:p>}},
  author       = {{Bauch, David and Siebert, Dustin and Jöns, Klaus D. and Förstner, Jens and Schumacher, Stefan}},
  issn         = {{2511-9044}},
  journal      = {{Advanced Quantum Technologies}},
  number       = {{1}},
  publisher    = {{Wiley}},
  title        = {{{On‐Demand Indistinguishable and Entangled Photons Using Tailored Cavity Designs}}},
  doi          = {{10.1002/qute.202300142}},
  volume       = {{7}},
  year         = {{2023}},
}

@article{61266,
  abstract     = {{<jats:p>This review examines the use of continuous-variable spectroscopy techniques for investigating quantum coherence and light-matter interactions in semiconductor systems with ultrafast dynamics. Special emphasis is placed on multichannel homodyne detection as a powerful tool to measure the quantum coherence and the full density matrix of a polariton system. Observations, such as coherence times that exceed the nanosecond scale obtained by monitoring the temporal decay of quantum coherence in a polariton condensate, are discussed. Proof-of-concept experiments and numerical simulations that demonstrate the enhanced resourcefulness of the produced system states for modern quantum protocols are assessed. The combination of tailored resource quantifiers and ultrafast spectroscopy techniques that have recently been demonstrated paves the way for future applications of quantum information technologies.</jats:p>}},
  author       = {{Lüders, Carolin and Barkhausen, Franziska and Pukrop, Matthias and Rozas, Elena and Sperling, Jan and Schumacher, Stefan and Aßmann, Marc}},
  issn         = {{2159-3930}},
  journal      = {{Optical Materials Express}},
  number       = {{11}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Continuous-variable quantum optics and resource theory for ultrafast semiconductor spectroscopy [Invited]}}},
  doi          = {{10.1364/ome.497006}},
  volume       = {{13}},
  year         = {{2023}},
}

@article{61264,
  author       = {{Yu, Yueyang and Dong, Chuan-Ding and Binder, Rolf and Schumacher, Stefan and Ning, Cun-Zheng}},
  issn         = {{1936-0851}},
  journal      = {{ACS Nano}},
  number       = {{5}},
  pages        = {{4230--4238}},
  publisher    = {{American Chemical Society (ACS)}},
  title        = {{{Strain-Induced Indirect-to-Direct Bandgap Transition, Photoluminescence Enhancement, and Linewidth Reduction in Bilayer MoTe<sub>2</sub>}}},
  doi          = {{10.1021/acsnano.2c01665}},
  volume       = {{17}},
  year         = {{2023}},
}

@article{61269,
  author       = {{Gao, Ying and Ma, Xuekai and Zhai, Xiaokun and Xing, Chunzi and Gao, Meini and Dai, Haitao and Wu, Hao and Liu, Tong and Ren, Yuan and Wang, Xiao and Pan, Anlian and Hu, Wei and Schumacher, Stefan and Gao, Tingge}},
  issn         = {{2469-9950}},
  journal      = {{Physical Review B}},
  number       = {{20}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Single-shot spatial instability and electric control of polariton condensates at room temperature}}},
  doi          = {{10.1103/physrevb.108.205303}},
  volume       = {{108}},
  year         = {{2023}},
}

@article{61267,
  abstract     = {{<jats:p>Dynamics-induced interchain charge transfer in a polymer aggregate in stack configuration can be understood by single-oligomer polaron energy.</jats:p>}},
  author       = {{Bauch, Fabian and Dong, Chuan-Ding and Schumacher, Stefan}},
  issn         = {{2050-7526}},
  journal      = {{Journal of Materials Chemistry C}},
  number       = {{38}},
  pages        = {{12992--12998}},
  publisher    = {{Royal Society of Chemistry (RSC)}},
  title        = {{{Dynamics-induced charge transfer in semiconducting conjugated polymers}}},
  doi          = {{10.1039/d3tc02263c}},
  volume       = {{11}},
  year         = {{2023}},
}

@inproceedings{61362,
  abstract     = {{<jats:p>We study the interaction of gray tracking and DC ionic conductivity in Potassium Titanyl Phosphate (KTiOPO<jats:sub>4</jats:sub>, KTP) and present a novel way to reduce conductivity via a potassium nitrate treatment improving the device quality.</jats:p>}},
  author       = {{Eigner, Christof and Padberg, Laura and Quiring, Viktor and Bocchini, Adriana and Santandrea, Matteo and Gerstmann, Uwe and Schmidt, Wolf Gero and Silberhorn, Christine}},
  booktitle    = {{CLEO 2023}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Potassium Titanyl Phosphate Material Engineering Boosting Integrated Optical Source Performance}}},
  doi          = {{10.1364/cleo_at.2023.jw2a.57}},
  year         = {{2023}},
}

@inbook{61360,
  author       = {{Hajduk, Andreas and Zare Pour, Mohammad Amin and Paszuk, Agnieszka and Guidat, Margot and Löw, Mario and Ullmann, Fabian and Moritz, Dominik C. and Hofmann, Jan P. and Krischok, Stefan and Runge, Erich and Schmidt, Wolf Gero and Jaegermann, Wolfram and May, Matthias M. and Hannappel, Thomas}},
  booktitle    = {{Encyclopedia of Solid-Liquid Interfaces}},
  isbn         = {{9780323856706}},
  publisher    = {{Elsevier}},
  title        = {{{(Photo-)electrochemical reactions on semiconductor surfaces, part B: III-V surfaces–atomic and electronic structure}}},
  doi          = {{10.1016/b978-0-323-85669-0.00113-6}},
  year         = {{2023}},
}

@article{40274,
  author       = {{Zhai, Xiaokun and Ma, Xuekai and Gao, Ying and Xing, Chunzi and Gao, Meini and Dai, Haitao and Wang, Xiao and Pan, Anlian and Schumacher, Stefan and Gao, Tingge}},
  journal      = {{Physical Review Letters}},
  number       = {{13}},
  pages        = {{136901}},
  title        = {{{Electrically controlling vortices in a neutral exciton polariton condensate at room temperature}}},
  doi          = {{10.1103/PhysRevLett.131.136901}},
  volume       = {{131}},
  year         = {{2023}},
}

@article{36416,
  author       = {{De, Jianbo and Ma, Xuekai and Yin, Fan and Ren, Jiahuan and Yao, Jiannian and Schumacher, Stefan and Liao, Qing and Fu, Hongbing and Malpuech, Guillaume and Solnyshkov, Dmitry}},
  issn         = {{0002-7863}},
  journal      = {{Journal of the American Chemical Society (JACS)}},
  keywords     = {{Colloid and Surface Chemistry, Biochemistry, General Chemistry, Catalysis}},
  number       = {{3}},
  pages        = {{1557--1563}},
  publisher    = {{American Chemical Society (ACS)}},
  title        = {{{Room-Temperature Electrical Field-Enhanced Ultrafast Switch in Organic Microcavity Polariton Condensates}}},
  doi          = {{10.1021/jacs.2c07557}},
  volume       = {{145}},
  year         = {{2023}},
}

@article{35077,
  author       = {{Liang, Qian and Ma, Xuekai and Long, Teng and Yao, Jiannian and Liao, Qing and Fu, Hongbing}},
  issn         = {{1433-7851}},
  journal      = {{Angewandte Chemie International Edition}},
  keywords     = {{General Chemistry, Catalysis}},
  number       = {{9}},
  publisher    = {{Wiley}},
  title        = {{{Circularly Polarized Lasing from a Microcavity Filled with Achiral Single‐Crystalline Microribbons}}},
  doi          = {{10.1002/anie.202213229}},
  volume       = {{62}},
  year         = {{2023}},
}

@article{36471,
  abstract     = {{<jats:p>Superconducting nanowire single-photon detectors (SNSPDs) show near unity efficiency, low dark count rate, and short recovery time. Combining these characteristics with temporal control of SNSPDs broadens their applications as in active de-latching for higher dynamic range counting or temporal filtering for pump-probe spectroscopy or LiDAR. To that end, we demonstrate active gating of an SNSPD with a minimum off-to-on rise time of 2.4 ns and a total gate length of 5.0 ns. We show how the rise time depends on the inductance of the detector in combination with the control electronics. The gate window is demonstrated to be fully and freely, electrically tunable up to 500 ns at a repetition rate of 1.0 MHz, as well as ungated, free-running operation. Control electronics to generate the gating are mounted on the 2.3 K stage of a closed-cycle sorption cryostat, while the detector is operated on the cold stage at 0.8 K. We show that the efficiency and timing jitter of the detector is not altered during the on-time of the gating window. We exploit gated operation to demonstrate a method to increase in the photon counting dynamic range by a factor 11.2, as well as temporal filtering of a strong pump in an emulated pump-probe experiment.</jats:p>}},
  author       = {{Hummel, Thomas and Widhalm, Alex and Höpker, Jan Philipp and Jöns, Klaus and Chang, Jin and Fognini, Andreas and Steinhauer, Stephan and Zwiller, Val and Zrenner, Artur and Bartley, Tim}},
  issn         = {{1094-4087}},
  journal      = {{Optics Express}},
  keywords     = {{Atomic and Molecular Physics, and Optics}},
  number       = {{1}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Nanosecond gating of superconducting nanowire single-photon detectors using cryogenic bias circuitry}}},
  doi          = {{10.1364/oe.472058}},
  volume       = {{31}},
  year         = {{2023}},
}

@article{63043,
  abstract     = {{Spatial modes of light have become highly attractive to increase the dimension and, thereby, security and information capacity in quantum key distribution (QKD). So far, only transverse electric field components have been considered, while longitudinal polarization components have remained neglected. Here, we present an approach to include all three spatial dimensions of electric field oscillation in QKD by implementing our tunable, on-a-chip vector beam decoder (VBD). This inversely designed device pioneers the "preparation" and "measurement" of three-dimensionally polarized mutually unbiased basis states for high-dimensional (HD) QKD and paves the way for the integration of HD QKD with spatial modes in multifunctional on-a-chip photonics platforms.}},
  title        = {{{Tunable vector beam decoder by inverse design for high-dimensional quantum key distribution with 3D polarized spatial modes}}},
  doi          = {{10.48550/ARXIV.2304.12296}},
  year         = {{2023}},
}

@inproceedings{45578,
  abstract     = {{A frequency-flexible Nyquist pulse synthesizer is presented with optical pulse bandwidths up to fopt=100 GHz and repetition rates equal to fopt/9, fabricated in an electronic-photonic co-integrated platform utilizing linear on-chip drivers.}},
  author       = {{Kress, Christian and Schwabe, Tobias and Silberhorn, Christine and Scheytt, J. Christoph}},
  booktitle    = {{ Conference on Lasers and Electro-Optics (CLEO) 2023}},
  location     = {{San Jose, CA, USA}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Generation of 100 GHz Periodic Nyquist Pulses using Cascaded Mach-Zehnder Modulators in a Silicon Electronic-Photonic Platform}}},
  doi          = {{https://doi.org/10.1364/CLEO_SI.2023.SF1P.6}},
  year         = {{2023}},
}

@article{46468,
  author       = {{Lange, Nina Amelie and Schapeler, Timon and Höpker, Jan Philipp and Protte, Maximilian and Bartley, Tim}},
  issn         = {{2469-9926}},
  journal      = {{Physical Review A}},
  number       = {{2}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Degenerate photons from a cryogenic spontaneous parametric down-conversion source}}},
  doi          = {{10.1103/physreva.108.023701}},
  volume       = {{108}},
  year         = {{2023}},
}

@article{41035,
  author       = {{Sharapova, Polina R. and Kruk, Sergey S. and Solntsev, Alexander S.}},
  issn         = {{1863-8880}},
  journal      = {{Laser &amp; Photonics Reviews}},
  keywords     = {{Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials}},
  publisher    = {{Wiley}},
  title        = {{{Nonlinear Dielectric Nanoresonators and Metasurfaces: Toward Efficient Generation of Entangled Photons}}},
  doi          = {{10.1002/lpor.202200408}},
  year         = {{2023}},
}

@article{57677,
  abstract     = {{<jats:p>We present the fabrication of strain-free quantum dots in the In0.53Ga0.47As/In0.52Al0.48As-system lattice matched to InP, as future sources for single and entangled photons for long-haul fiber-based quantum communication in the optical C-band. We achieved these quantum dots by local droplet etching via InAl droplets in an In0.52Al0.48As layer and subsequent filling of the holes with In0.53Ga0.47As. Here, we present detailed investigations of the hole morphologies measured by atomic force microscopy. Statistical analysis of a set of nanoholes reveals a high degree of symmetry for nearly half of them when etched at optimized temperatures. Overgrowth with 50–150 nm In0.52Al0.48As increases their diameter and elongates the holes along the [01̄1]-direction. By systematically scanning the parameter space, we were able to fill the holes with In0.53Ga0.47As, and by capping the filled holes and performing photoluminescence measurements, we observe photoluminescence emission in the O-band up into the C-band depending on the filling height of the nanoholes.</jats:p>}},
  author       = {{Deutsch, Dennis and Buchholz, C. and Zolatanosha, V. and Jöns, K. D. and Reuter, Dirk}},
  issn         = {{2158-3226}},
  journal      = {{AIP Advances}},
  number       = {{5}},
  publisher    = {{AIP Publishing}},
  title        = {{{Telecom C-band photon emission from (In,Ga)As quantum dots generated by filling nanoholes in In0.52Al0.48As layers}}},
  doi          = {{10.1063/5.0147281}},
  volume       = {{13}},
  year         = {{2023}},
}

@inproceedings{47521,
  abstract     = {{This paper experimentally investigates and interprets the e®ects of noise and non-
linearity in a silicon photonic optical test structure. For the analysis di®erent optoelectronic phase
noise measurement techniques are used. Our tests focuses on the performance of integrated opti-
cal test structures using femtosecond pulses in the 1550nm spectral range. A primary objective
is to understand the behaviour of silicon photonic waveguides that can be further employed in the
implementation of an optoelectronic phase-locked loop (OEPLL) in silicon photonics technology.
A comparison of our results, as well as a discussion on the di®erent optoelectronic phase noise
measurement techniques are presented. Our ¯ndings provide insights that can be leveraged to
optimize the design and performance of ultra-low phase noise on-chip OEPLL systems locking
to mode-locked laser (MLL) signals. In the future such systems can be essential for advanced
communication and sensing applications.}},
  author       = {{Surendranath Shroff, Vijayalakshmi and Kress, Christian and Bahmanian, Meysam and Scheytt, J. Christoph}},
  booktitle    = {{2023 PhotonIcs & Electromagnetics Research Symposium (PIERS), }},
  location     = {{Prague, Czech Republic}},
  publisher    = {{IEEE}},
  title        = {{{Analysis of Phase Noise in Waveguide-integrated Optical Test Structures in Silicon Photonics}}},
  doi          = {{10.1109/PIERS59004.2023.10221473}},
  year         = {{2023}},
}

@inproceedings{42800,
  abstract     = {{In this paper we present a new system architecture for software-defined radio / radar with optical signal distribution. The proposed architecture allows to transmit the optical carrier and an arbitrary IQ signal on the same fiber from a base station to wireless transmitters using a single laser. Furthermore, we can reuse parts, and under special conditions, also the complete optical output of the base station for the IQ return path from the wireless receiver frontends to the base station. Avoiding multiple lasers and fibers for the distribution of the carrier and arbitrary signal from the base station to the frontend, and avoiding the laser diode for the IQ return path from receiver frontends to the base station reduces the hardware effort significantly. Finally, the system architecture allows to integrate all components of the optoelectronic wireless frontend in a single chip using silicon photonics technology.}},
  author       = {{Kruse, Stephan and Kneuper, Pascal and Schwabe, Tobias and Meinecke, Marc-Michael and Kurz, Heiko G. and Scheytt, J. Christoph}},
  location     = {{Fraunhofer-Forum Berlin, Germany}},
  title        = {{{Distributed System Architecture for Software-Defined Radio / Radar with Optical Signal Distribution}}},
  doi          = {{10.23919/IRS57608.2023.10172470}},
  year         = {{2023}},
}

@article{47126,
  author       = {{Kruse, Stephan and Greitens, Jan C. and Schwabe, Tobias and Kneuper, Pascal and Kurz, Heiko G. and Scheytt, J. Christoph}},
  journal      = {{IEEE Microwave and Wireless Technology Letters }},
  title        = {{{A Narrowband Four-Quadrant Electro-Optical Mixer for Microwave Photonics}}},
  doi          = {{10.1109/LMWT.2023.3315315}},
  year         = {{2023}},
}

@inproceedings{42804,
  abstract     = {{This paper presents a method to model monolithically integrated photonic radar transceiver (TRX) with optical local oscillator (LO) distribution in silicon germanium (SiGe) electronic photonic integrated circuits (EPICs). The model proposed approximates the behavior of the nonlinear scattering (S)-parameters and noise figure of each building block of the TRX chipset by Laplace polynomials and hyperbolic tangent functions. The modular approach of the model allows to optimize hardware components with respect to the entire TRX system, and fault identification with reduced computational effort.
The proposed method is validated using the first monolithically integrated photonic radar transceiver chipset and shows excellent agreement with the post layout simulation results and, including the photodiode (PD) bandwidth (BW) degradation, also with the measurements.
}},
  author       = {{Kruse, Stephan and Schwabe, Tobias and Kneuper, Pascal and Meinecke, Marc-Michael and Kurz, Heiko G. and Scheytt, J. Christoph}},
  location     = {{Fraunhofer-Forum Berlin, Germany}},
  title        = {{{Nonlinear S-Parameter Behavioral Model of a Photonic Radar Transceiver Chipset for Automotive Applications}}},
  doi          = {{10.23919/IRS57608.2023.10172395}},
  year         = {{2023}},
}