@article{37334, abstract = {{Uniaxial anisotropy in nonlinear birefringent crystals limits the efficiency of nonlinear optical interactions and breaks the spatial symmetry of light generated in the parametric down-conversion (PDC) process. Therefore, this effect is usually undesirable and must be compensated for. However, high gain may be used to overcome the destructive role of anisotropy in order to generate bright two-mode correlated twin-beams. In this work, we provide a rigorous theoretical description of the spatial properties of bright squeezed light in the presence of strong anisotropy. We investigate a single crystal and a system of two crystals with an air gap (corresponding to a nonlinear SU(1,1) interferometer) and demonstrate the generation of bright correlated twin-beams in such configurations at high gain due to anisotropy. We explore the mode structure of the generated light and show how anisotropy, together with crystal spacing, can be used for radiation shaping.}}, author = {{Riabinin, M. and Sharapova, Polina and Meier, Torsten}}, issn = {{1094-4087}}, journal = {{Optics Express}}, keywords = {{Atomic and Molecular Physics, and Optics}}, number = {{14}}, pages = {{21876--21890}}, publisher = {{Optica Publishing Group}}, title = {{{Bright correlated twin-beam generation and radiation shaping in high-gain parametric down-conversion with anisotropy}}}, doi = {{10.1364/oe.424977}}, volume = {{29}}, year = {{2021}}, } @article{29209, abstract = {{We demonstrate an optical arbitrary waveform measurement (OAWM) system that exploits a bank of silicon photonic (SiP) frequency-tunable coupled-resonator optical waveguide (CROW) filters for gapless spectral slicing of broadband optical signals. The spectral slices are coherently detected using a frequency comb as a multi-wavelength local oscillator (LO) and stitched together by digital signal processing (DSP). For high-quality signal reconstruction, we have implemented a maximum-ratio combining (MRC) technique based on precise calibration of the complex-valued opto-electronic transfer functions of all detection paths. In a proof-of-concept experiment, we demonstrate the viability of the scheme by implementing a four-channel system that offers an overall detection bandwidth of 140 GHz. Exploiting a femtosecond laser with precisely known pulse shape for calibration along with dynamic amplitude and phase estimation, we reconstruct 100 GBd QPSK, 16QAM and 64QAM optical data signals. The reconstructed signals show improved quality compared to that obtained with a single high-speed intradyne receiver, while the electronic bandwidth requirements of the individual coherent receivers are greatly reduced.}}, author = {{Fang, Dengyang and Zazzi, Andrea and Müller, Juliana and Dray, Daniel and Fullner, Christoph and Marin-Palomo, Pablo and Tabatabaei Mashayekh, Alireza and Dipta Das, Arka and Weizel, Maxim and Gudyriev, Sergiy and Freude, Wolfgang and Randel, Sebastian and Scheytt, J. Christoph and Witzens, Jeremy and Koos, Christian}}, issn = {{0733-8724}}, journal = {{Journal of Lightwave Technology}}, keywords = {{Atomic and Molecular Physics, and Optics}}, pages = {{1--1}}, publisher = {{Institute of Electrical and Electronics Engineers (IEEE)}}, title = {{{Optical Arbitrary Waveform Measurement Using Silicon Photonic Slicing Filters}}}, doi = {{10.1109/jlt.2021.3130764}}, year = {{2021}}, } @article{40379, author = {{Sukharnikov, Vladislav and Sharapova, Polina and Tikhonova, Olga}}, issn = {{0030-3992}}, journal = {{Optics & Laser Technology}}, keywords = {{Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials}}, publisher = {{Elsevier BV}}, title = {{{Managing spectral properties and Schmidt mode content of squeezed vacuum light using sum-frequency converter}}}, doi = {{10.1016/j.optlastec.2020.106769}}, volume = {{136}}, year = {{2021}}, } @article{35723, abstract = {{The development of renewable energies and smart mobility has profoundly impacted the future of the distribution grid. An increasing bidirectional energy flow stresses the assets of the distribution grid, especially medium voltage switchgear. This calls for improved maintenance strategies to prevent critical failures. Predictive maintenance, a maintenance strategy relying on current condition data of assets, serves as a guideline. Novel sensors covering thermal, mechanical, and partial discharge aspects of switchgear, enable continuous condition monitoring of some of the most critical assets of the distribution grid. Combined with machine learning algorithms, the demands put on the distribution grid by the energy and mobility revolutions can be handled. In this paper, we review the current state-of-the-art of all aspects of condition monitoring for medium voltage switchgear. Furthermore, we present an approach to develop a predictive maintenance system based on novel sensors and machine learning. We show how the existing medium voltage grid infrastructure can adapt these new needs on an economic scale.}}, author = {{Hoffmann, Martin W. and Wildermuth, Stephan and Gitzel, Ralf and Boyaci, Aydin and Gebhardt, Jörg and Kaul, Holger and Amihai, Ido and Forg, Bodo and Suriyah, Michael and Leibfried, Thomas and Stich, Volker and Hicking, Jan and Bremer, Martin and Kaminski, Lars and Beverungen, Daniel and zur Heiden, Philipp and Tornede, Tanja}}, issn = {{1424-8220}}, journal = {{Sensors}}, keywords = {{Electrical and Electronic Engineering, Biochemistry, Instrumentation, Atomic and Molecular Physics, and Optics, Analytical Chemistry}}, number = {{7}}, publisher = {{MDPI AG}}, title = {{{Integration of Novel Sensors and Machine Learning for Predictive Maintenance in Medium Voltage Switchgear to Enable the Energy and Mobility Revolutions}}}, doi = {{10.3390/s20072099}}, volume = {{20}}, year = {{2020}}, } @article{34088, author = {{Bürger, Julius and Riedl, Thomas and Lindner, Jörg}}, issn = {{0304-3991}}, journal = {{Ultramicroscopy}}, keywords = {{Instrumentation, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials}}, publisher = {{Elsevier BV}}, title = {{{Influence of lens aberrations, specimen thickness and tilt on differential phase contrast STEM images}}}, doi = {{10.1016/j.ultramic.2020.113118}}, volume = {{219}}, year = {{2020}}, } @article{47958, abstract = {{High-fidelity periodic poling over long lengths is required for robust, quasi-phase-matched second-harmonic generation using the fundamental, quasi-TE polarized waveguide modes in a thin-film lithium niobate (TFLN) waveguide. Here, a shallow-etched ridge waveguide is fabricated in x-cut magnesium oxide doped TFLN and is poled accurately over 5 mm. The high fidelity of the poling is demonstrated over long lengths using a non-destructive technique of confocal scanning second-harmonic microscopy. We report a second-harmonic conversion efficiency of up to 939 %/W (length-normalized conversion efficiency 3757 %/Wcm²), measured at telecommunications wavelengths. The device demonstrates a narrow spectral linewidth (1 nm) and can be tuned precisely with a tuning characteristic of 0.1 nm/°C, over at least 40 °C without measurable loss of efficiency.}}, author = {{Zhao, Jie and Rüsing, Michael and Javid, Usman A. and Ling, Jingwei and Li, Mingxiao and Lin, Qiang and Mookherjea, Shayan}}, issn = {{1094-4087}}, journal = {{Optics Express}}, keywords = {{Atomic and Molecular Physics, and Optics}}, number = {{13}}, publisher = {{Optica Publishing Group}}, title = {{{Shallow-etched thin-film lithium niobate waveguides for highly-efficient second-harmonic generation}}}, doi = {{10.1364/oe.395545}}, volume = {{28}}, year = {{2020}}, } @article{35869, author = {{Keum, Changmin and Becker, David and Archer, Emily and Bock, Harald and Kitzerow, Heinz-Siegfried and Gather, Malte C. and Murawski, Caroline}}, issn = {{2195-1071}}, journal = {{Advanced Optical Materials}}, keywords = {{Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials}}, number = {{17}}, publisher = {{Wiley}}, title = {{{Organic Light‐Emitting Diodes Based on a Columnar Liquid‐Crystalline Perylene Emitter}}}, doi = {{10.1002/adom.202000414}}, volume = {{8}}, year = {{2020}}, } @article{40217, author = {{Wagenknecht, Inga and Meier-Gräwe, Uta}}, issn = {{2196-8225}}, journal = {{Praxis der Kinderpsychologie und Kinderpsychiatrie}}, keywords = {{Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics}}, number = {{7}}, pages = {{643--665}}, publisher = {{Vandenhoeck & Ruprecht GmbH & Co, KG}}, title = {{{Psychische Auffälligkeiten bei Kindern und Jugendlichen, für die das Jugendamt in Anspruch genommen wurde}}}, doi = {{10.13109/prkk.2020.69.7.643}}, volume = {{69}}, year = {{2020}}, } @article{37934, author = {{Mukamel, Shaul and Freyberger, Matthias and Schleich, Wolfgang and Bellini, Marco and Zavatta, Alessandro and Leuchs, Gerd and Silberhorn, Christine and Boyd, Robert W and Sánchez-Soto, Luis Lorenzo and Stefanov, André and Barbieri, Marco and Paterova, Anna and Krivitsky, Leonid and Shwartz, Sharon and Tamasaku, Kenji and Dorfman, Konstantin and Schlawin, Frank and Sandoghdar, Vahid and Raymer, Michael and Marcus, Andrew and Varnavski, Oleg and Goodson, Theodore and Zhou, Zhi-Yuan and Shi, Bao-Sen and Asban, Shahaf and Scully, Marlan and Agarwal, Girish and Peng, Tao and Sokolov, Alexei V and Zhang, Zhe-Dong and Zubairy, M Suhail and Vartanyants, Ivan A and del Valle, Elena and Laussy, Fabrice}}, issn = {{0953-4075}}, journal = {{Journal of Physics B: Atomic, Molecular and Optical Physics}}, keywords = {{Condensed Matter Physics, Atomic and Molecular Physics, and Optics}}, number = {{7}}, publisher = {{IOP Publishing}}, title = {{{Roadmap on quantum light spectroscopy}}}, doi = {{10.1088/1361-6455/ab69a8}}, volume = {{53}}, year = {{2020}}, } @article{37932, abstract = {{Hybrid quantum information processing combines the advantages of discrete and continues variable protocols by realizing protocols consisting of photon counting and homodyne measurements. However, the mode structure of pulsed sources and the properties of the detection schemes often require the use of optical filters in order to combine both detection methods in a common experiment. This limits the efficiency and the overall achievable squeezing of the experiment. In our work, we use photon subtraction to implement the distillation of pulsed squeezed states originating from a genuinely spatially and temporally single-mode parametric down-conversion source in non-linear waveguides. Due to the distillation, we witness an improvement of 0.17 dB from an initial squeezing value of −1.648 ± 0.002 dB, while achieving a purity of 0.58, and confirm the non-Gaussianity of the distilled state via the higher-order cumulants. With this, we demonstrate the source’s suitability for scalable hybrid quantum network applications with pulsed quantum light.}}, author = {{Dirmeier, Thomas and Tiedau, Johannes and Khan, Imran and Ansari, Vahid and Müller, Christian R. and Silberhorn, Christine and Marquardt, Christoph and Leuchs, Gerd}}, issn = {{1094-4087}}, journal = {{Optics Express}}, keywords = {{Atomic and Molecular Physics, and Optics}}, number = {{21}}, publisher = {{Optica Publishing Group}}, title = {{{Distillation of squeezing using an engineered pulsed parametric down-conversion source}}}, doi = {{10.1364/oe.402178}}, volume = {{28}}, year = {{2020}}, } @article{40438, abstract = {{Semiconductor microcavities are frequently studied in the context of semiconductor lasers and in application-oriented fundamental research on topics such as linear and nonlinear polariton systems, polariton lasers, polariton pattern formation, and polaritonic Bose–Einstein condensates. A commonly used approach to describe theoretical properties includes a phenomenological single-mode equation that complements the equation for the nonlinear optical response (interband polarization) of the semiconductor. Here, we show how to replace the single-mode equation by a fully predictive transfer function method that, in contrast to the single-mode equation, accounts for propagation, retardation, and pulse-filtering effects of the incident light field traversing the distributed Bragg reflector (DBR) mirrors, without substantially increasing the numerical complexity of the solution. As examples, we use cavities containing GaAs quantum wells and transition-metal dichalcogenides (TMDs).}}, author = {{Carcamo, M. and Schumacher, Stefan and Binder, R.}}, issn = {{1559-128X}}, journal = {{Applied Optics}}, keywords = {{Atomic and Molecular Physics, and Optics, Engineering (miscellaneous), Electrical and Electronic Engineering}}, number = {{22}}, publisher = {{Optica Publishing Group}}, title = {{{Transfer function replacement of phenomenological single-mode equations in semiconductor microcavity modeling}}}, doi = {{10.1364/ao.392014}}, volume = {{59}}, year = {{2020}}, } @article{38051, abstract = {{The characterisation of loss in optical waveguides is essential in understanding the performance of these devices and their limitations. Whilst interferometric-based methods generally provide the best results for low-loss waveguides, they are almost exclusively used to provide characterization in cases where the waveguide is spatially single-mode. Here, we introduce a Fabry-Pérot-based scheme to estimate the losses of a nonlinear (birefringent or quasi-phase matched) waveguide at a wavelength where it is multi-mode. The method involves measuring the generated second harmonic power as the pump wavelength is scanned over the phase matching region. Furthermore, it is shown that this method allows one to infer the losses of different second harmonic spatial modes by scanning the pump field over the separated phase matching spectra. By fitting the measured phase matching spectra from different titanium indiffused lithium niobate waveguides to the model presented in this paper, it is shown that one can estimate the second harmonic losses of a single spatial-mode, at wavelengths where the waveguides are spatially multi-mode.}}, author = {{Santandrea, Matteo and Stefszky, Michael and Roeland, Ganaël and Silberhorn, Christine}}, issn = {{1094-4087}}, journal = {{Optics Express}}, keywords = {{Atomic and Molecular Physics, and Optics}}, number = {{4}}, publisher = {{Optica Publishing Group}}, title = {{{Interferometric method for determining the losses of spatially multi-mode nonlinear waveguides based on second harmonic generation.}}}, doi = {{10.1364/oe.380788}}, volume = {{28}}, year = {{2020}}, } @article{40381, abstract = {{Abstract The phenomenon of entanglement is the basis of quantum information and quantum communication processes. Entangled systems with a large number of photons are of great interest at present because they provide a platform for streaming technologies based on photonics. In this paper we present a device which operates with four-photons and based on the Hong–Ou–Mandel interference. The presented device allows to maximize the degree of spatial entanglement and generate the highly entangled four-dimensional Bell states. Furthermore, the use of the interferometer in different regimes leads to fast interference fringes in the coincidence probability with period of oscillations twice smaller than the pump wavelength. We have a good agreement between theoretical simulations and experimental results.}}, author = {{Ferreri, A and Ansari, V and Brecht, Benjamin and Silberhorn, Christine and Sharapova, Polina R.}}, issn = {{2058-9565}}, journal = {{Quantum Science and Technology}}, keywords = {{Electrical and Electronic Engineering, Physics and Astronomy (miscellaneous), Materials Science (miscellaneous), Atomic and Molecular Physics, and Optics}}, number = {{4}}, publisher = {{IOP Publishing}}, title = {{{Spatial entanglement and state engineering via four-photon Hong–Ou–Mandel interference}}}, doi = {{10.1088/2058-9565/abb411}}, volume = {{5}}, year = {{2020}}, } @article{37933, abstract = {{We present a time-over-threshold readout technique to count the number of activated pixels from an array of superconducting nanowire single photon detectors (SNSPDs). This technique places no additional heatload on the cryostat, and retains the intrinsic count rate of the time-tagger. We demonstrate proof-of-principle operation with respect to a four-pixel device. Furthermore, we show that, given some permissible error threshold, the number of pixels that can be reliably read out scales linearly with the intrinsic signal-to-noise ratio of the individual pixel response.}}, author = {{Tiedau, Johannes and Schapeler, Timon and Anant, Vikas and Fedder, Helmut and Silberhorn, Christine and Bartley, Tim}}, issn = {{1094-4087}}, journal = {{Optics Express}}, keywords = {{Atomic and Molecular Physics, and Optics}}, number = {{4}}, publisher = {{Optica Publishing Group}}, title = {{{Single-channel electronic readout of a multipixel superconducting nanowire single photon detector}}}, doi = {{10.1364/oe.383111}}, volume = {{28}}, year = {{2020}}, } @article{47946, author = {{Zhao, Jie and Rüsing, Michael and Mookherjea, Shayan}}, issn = {{1094-4087}}, journal = {{Optics Express}}, keywords = {{Atomic and Molecular Physics, and Optics}}, number = {{9}}, publisher = {{The Optical Society}}, title = {{{Optical diagnostic methods for monitoring the poling of thin-film lithium niobate waveguides}}}, doi = {{10.1364/oe.27.012025}}, volume = {{27}}, year = {{2019}}, } @article{47948, abstract = {{Mach-Zehnder electro-optic modulators (EOM) based on thin-film lithium niobate bonded to a silicon photonic waveguide circuit have been shown to achieve very high modulation bandwidths. Open eye-diagram measurements made in the time domain of beyond-small-signal modulation are used to support the modulation-sideband measurements in showing that such EOM’s can support high-frequency modulations well beyond 100 GHz.}}, author = {{Wang, Xiaoxi and Weigel, Peter O. and Zhao, Jie and Rüsing, Michael and Mookherjea, Shayan}}, issn = {{2378-0967}}, journal = {{APL Photonics}}, keywords = {{Computer Networks and Communications, Atomic and Molecular Physics, and Optics}}, number = {{9}}, publisher = {{AIP Publishing}}, title = {{{Achieving beyond-100-GHz large-signal modulation bandwidth in hybrid silicon photonics Mach Zehnder modulators using thin film lithium niobate}}}, doi = {{10.1063/1.5115243}}, volume = {{4}}, year = {{2019}}, } @article{35872, author = {{Zhang, Bingru and Schmidtke, Jürgen and Kitzerow, Heinz-Siegfried}}, issn = {{2195-1071}}, journal = {{Advanced Optical Materials}}, keywords = {{Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials}}, number = {{8}}, publisher = {{Wiley}}, title = {{{Fabrication of Lyotropic Alignment Layers for Thermotropic Liquid Crystals Facilitated by a Polymer Template}}}, doi = {{10.1002/adom.201801766}}, volume = {{7}}, year = {{2019}}, } @article{38047, author = {{Xie, Zhenda and Luo, Kai Hong and Chang, Kai Chi and Panoiu, Nicolae C. and Herrmann, Harald and Silberhorn, Christine and Wong, Chee Wei}}, issn = {{1559-128X}}, journal = {{Applied Optics}}, keywords = {{Atomic and Molecular Physics, and Optics, Engineering (miscellaneous), Electrical and Electronic Engineering}}, number = {{22}}, publisher = {{The Optical Society}}, title = {{{Efficient C-band single-photon upconversion with chip-scale Ti-indiffused pp-LiNbO3 waveguides}}}, doi = {{10.1364/ao.58.005910}}, volume = {{58}}, year = {{2019}}, } @article{38052, author = {{Montaut, Nicola and Magaña-Loaiza, Omar S. and Bartley, Tim and Verma, Varun B. and Nam, Sae Woo and Mirin, Richard P. and Silberhorn, Christine and Gerrits, Thomas}}, issn = {{2334-2536}}, journal = {{Optica}}, keywords = {{Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials}}, number = {{11}}, publisher = {{The Optical Society}}, title = {{{Compressive characterization of telecom photon pairs in the spatial and spectral degrees of freedom}}}, doi = {{10.1364/optica.5.001418}}, volume = {{5}}, year = {{2018}}, } @article{46003, abstract = {{

Silver nanowire (Ag NW) based composites have shown a great potential not just in transparent electrodes but in diverse functional applications.

}}, author = {{Du, Haojin and Pan, Ying and Zhang, Xiao and Cao, Fuyang and Wan, Tao and Du, Haiwei and Joshi, Rakesh and Chu, Dewei}}, issn = {{2516-0230}}, journal = {{Nanoscale Advances}}, keywords = {{General Engineering, General Materials Science, General Chemistry, Atomic and Molecular Physics, and Optics, Bioengineering}}, number = {{1}}, pages = {{140--146}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{Silver nanowire/nickel hydroxide nanosheet composite for a transparent electrode and all-solid-state supercapacitor}}}, doi = {{10.1039/c8na00110c}}, volume = {{1}}, year = {{2018}}, }