@article{ElHelouBiegnerBodeetal.2019, author = {El-Helou, Sabine M. and Biegner, Anika-Kerstin and Bode, Sebastian and Ehl, Stephan R. and Heeg, Maximilian and Maccari, Maria E. and Ritterbusch, Henrike and Speckmann, Carsten and Rusch, Stephan and Scheible, Raphael and Warnatz, Klaus and Atschekzei, Faranaz and Beider, Renata and Ernst, Diana and Gerschmann, Stev and Jablonka, Alexandra and Mielke, Gudrun and Schmidt, Reinhold E. and Sch{\"u}rmann, Gesine and Sogkas, Georgios and Baumann, Ulrich H. and Klemann, Christian and Viemann, Dorothee and Bernuth, Horst von and Kr{\"u}ger, Renate and Hanitsch, Leif G. and Scheibenbogen, Carmen M. and Wittke, Kirsten and Albert, Michael H. and Eichinger, Anna and Hauck, Fabian and Klein, Christoph and Rack-Hoch, Anita and Sollinger, Franz M. and Avila, Anne and Borte, Michael and Borte, Stephan and Fasshauer, Maria and Hauenherm, Anja and Kellner, Nils and M{\"u}ller, Anna H. and {\"U}lzen, Anett and Bader, Peter and Bakhtiar, Shahrzad and Lee, Jae-Yun and Heß, Ursula and Schubert, Ralf and W{\"o}lke, Sandra and Zielen, Stefan and Ghosh, Sujal and Laws, Hans-Juergen and Neubert, Jennifer and Oommen, Prasad T. and H{\"o}nig, Manfred and Schulz, Ansgar and Steinmann, Sandra and Klaus, Schwarz and D{\"u}ckers, Gregor and Lamers, Beate and Langemeyer, Vanessa and Niehues, Tim and Shai, Sonu and Graf, Dagmar and M{\"u}glich, Carmen and Schmalzing, Marc T. and Schwaneck, Eva C. and Tony, Hans-Peter and Dirks, Johannes and Haase, Gabriele and Liese, Johannes G. and Morbach, Henner and Foell, Dirk and Hellige, Antje and Wittkowski, Helmut and Masjosthusmann, Katja and Mohr, Michael and Geberzahn, Linda and Hedrich, Christian M. and M{\"u}ller, Christiane and R{\"o}sen-Wolff, Angela and Roesler, Joachim and Zimmermann, Antje and Behrends, Uta and Rieber, Nikolaus and Schauer, Uwe and Handgretinger, Rupert and Holzer, Ursula and Henes, J{\"o}rg and Kanz, Lothar and Boesecke, Christoph and Rockstroh, J{\"u}rgen K. and Schwarze-Zander, Carolynne and Wasmuth, Jan-Christian and Dilloo, Dagmar and H{\"u}lsmann, Brigitte and Sch{\"o}nberger, Stefan and Schreiber, Stefan and Zeuner, Rainald and Ankermann, Tobias and Bismarck, Philipp von and Huppertz, Hans-Iko and Kaiser-Labusch, Petra and Greil, Johann and Jakoby, Donate and Kulozik, Andreas E. and Metzler, Markus and Naumann-Bartsch, Nora and Sobik, Bettina and Graf, Norbert and Heine, Sabine and Kobbe, Robin and Lehmberg, Kai and M{\"u}ller, Ingo and Herrmann, Friedrich and Horneff, Gerd and Klein, Ariane and Peitz, Joachim and Schmidt, Nadine and Bielack, Stefan and Groß-Wieltsch, Ute and Classen, Carl F. and Klasen, Jessica and Deutz, Peter and Kamitz, Dirk and Lassy, Lisa and Tenbrock, Klaus and Wagner, Norbert and Bernbeck, Benedikt and Brummel, Bastian and Lara-Villacanas, Eusebia and M{\"u}nstermann, Esther and Schneider, Dominik T. and Tietsch, Nadine and Westkemper, Marco and Weiß, Michael and Kramm, Christof and K{\"u}hnle, Ingrid and Kullmann, Silke and Girschick, Hermann and Specker, Christof and Vinnemeier-Laubenthal, Elisabeth and Haenicke, Henriette and Schulz, Claudia and Schweigerer, Lothar and M{\"u}ller, Thomas G. and Stiefel, Martina and Belohradsky, Bernd H. and Soetedjo, Veronika and Kindle, Gerhard and Grimbacher, Bodo}, title = {The German national registry of primary immunodeficiencies (2012-2017)}, series = {Frontiers in Immunology}, volume = {10}, journal = {Frontiers in Immunology}, doi = {10.3389/fimmu.2019.01272}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226629}, year = {2019}, abstract = {Introduction: The German PID-NET registry was founded in 2009, serving as the first national registry of patients with primary immunodeficiencies (PID) in Germany. It is part of the European Society for Immunodeficiencies (ESID) registry. The primary purpose of the registry is to gather data on the epidemiology, diagnostic delay, diagnosis, and treatment of PIDs. Methods: Clinical and laboratory data was collected from 2,453 patients from 36 German PID centres in an online registry. Data was analysed with the software Stata® and Excel. Results: The minimum prevalence of PID in Germany is 2.72 per 100,000 inhabitants. Among patients aged 1-25, there was a clear predominance of males. The median age of living patients ranged between 7 and 40 years, depending on the respective PID. Predominantly antibody disorders were the most prevalent group with 57\% of all 2,453 PID patients (including 728 CVID patients). A gene defect was identified in 36\% of patients. Familial cases were observed in 21\% of patients. The age of onset for presenting symptoms ranged from birth to late adulthood (range 0-88 years). Presenting symptoms comprised infections (74\%) and immune dysregulation (22\%). Ninety-three patients were diagnosed without prior clinical symptoms. Regarding the general and clinical diagnostic delay, no PID had undergone a slight decrease within the last decade. However, both, SCID and hyper IgE-syndrome showed a substantial improvement in shortening the time between onset of symptoms and genetic diagnosis. Regarding treatment, 49\% of all patients received immunoglobulin G (IgG) substitution (70\%-subcutaneous; 29\%-intravenous; 1\%-unknown). Three-hundred patients underwent at least one hematopoietic stem cell transplantation (HSCT). Five patients had gene therapy. Conclusion: The German PID-NET registry is a precious tool for physicians, researchers, the pharmaceutical industry, politicians, and ultimately the patients, for whom the outcomes will eventually lead to a more timely diagnosis and better treatment.}, language = {en} } @article{SchneiderHoehneSchneideretal.2022, author = {Schneider, Sonja Jasmin Maria and H{\"o}hne, Christian and Schneider, Martin and Schmitter, Marc}, title = {Photoacoustic tomography versus cone-beam computed tomography versus micro-computed tomography: Accuracy of 3D reconstructions of human teeth}, series = {PloS One}, volume = {17}, journal = {PloS One}, number = {12}, doi = {10.1371/journal.pone.0274818}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301437}, year = {2022}, abstract = {Objectives In this in-vitro study, teeth were imaged using photoacoustic tomography (PAT), cone-beam computed tomography (CBCT), and micro-computed tomography (μ-CT). The study had aim: to identify the best wavelength for PAT images to determine the accuracy of the three imaging methods, and to determine whether PAT images of teeth can achieve acceptable reconstruction quality. Methods Nineteen human mandibular single-rooted incisors were extracted from patients with trauma or periodontitis. To determine the best wavelength for acquiring photoacoustic images, all 19 teeth were scanned in vitro with PAT, using different laser wavelengths between 680 and 960 nm. The images were analyzed using image analysis software. To assess the accuracy of PAT and compare it with the accuracy of CBCT, each tooth was also scanned in vitro using CBCT and the reference standard technique of μ-CT. Subsequently, three different three-dimensional models, one for each imaging technique, were created for each tooth. Finally, the three different three-dimensional models acquired for the same tooth were matched and analyzed regarding volume and surface. Results The highest quality tooth images were achieved using the 680 nm wavelength, which showed the best contrast ratio. The full geometry of the dental root (μ-CT compared with PAT) could be visualized with relative standard deviations of 0.12 mm for the surface and -7.33 mm3 for the volume (n = 19). The full geometry of the dental root (μ-CT compared with CBCT) could be visualized with relative standard deviations of 0.06 mm for the surface and -14.56 mm3 for the volume (n = 19). The difference between the PAT-μ-CT group and CBCT-μ-CT group regarding the total average of the root surface area was not significant (p>0.06). Conclusion Images, which were acquired using PAT at 680nm showed the best contrast ration, enabling the identification of dentin, cementum and the dental pulp. No significant differences were found between the PAT-μ-CT group and CBCT-μ-CT group regarding the total average of the RSA and the total volume. Thus, three-dimensional reconstructions based on in-vitro PAT are already of acceptable reconstruction quality.}, language = {en} } @article{AeschlimannBauerBayeretal.2012, author = {Aeschlimann, Martin and Bauer, Michael and Bayer, Daniela and Brixner, Tobias and Cunovic, Stefan and Fischer, Alexander and Melchior, Pascal and Pfeiffer, Walter and Rohmer, Martin and Schneider, Christian and Str{\"u}ber, Christian and Tuchscherer, Philip and Voronine, Dimitri V.}, title = {Optimal open-loop near-field control of plasmonic nanostructures}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75256}, year = {2012}, abstract = {Optimal open-loop control, i.e. the application of an analytically derived control rule, is demonstrated for nanooptical excitations using polarization-shaped laser pulses. Optimal spatial near-field localization in gold nanoprisms and excitation switching is realized by applying a shift to the relative phase of the two polarization components. The achieved near-field switching confirms theoretical predictions, proves the applicability of predefined control rules in nanooptical light-matter interaction and reveals local mode interference to be an important control mechanism.}, subject = {Chemie}, language = {en} } @article{KochereshkoDurnevBesombesetal.2016, author = {Kochereshko, Vladimir P. and Durnev, Mikhail V. and Besombes, Lucien and Mariette, Henri and Sapega, Victor F. and Askitopoulos, Alexis and Savenko, Ivan G. and Liew, Timothy C. H. and Shelykh, Ivan A. and Platonov, Alexey V. and Tsintzos, Simeon I. and Hatzopoulos, Z. and Savvidis, Pavlos G. and Kalevich, Vladimir K. and Afanasiev, Mikhail M. and Lukoshkin, Vladimir A. and Schneider, Christian and Amthor, Matthias and Metzger, Christian and Kamp, Martin and Hoefling, Sven and Lagoudakis, Pavlos and Kavokin, Alexey}, title = {Lasing in Bose-Fermi mixtures}, series = {Scientific Reports}, volume = {6}, journal = {Scientific Reports}, number = {20091}, doi = {10.1038/srep20091}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-168152}, year = {2016}, abstract = {Light amplification by stimulated emission of radiation, well-known for revolutionising photonic science, has been realised primarily in fermionic systems including widely applied diode lasers. The prerequisite for fermionic lasing is the inversion of electronic population, which governs the lasing threshold. More recently, bosonic lasers have also been developed based on Bose-Einstein condensates of exciton-polaritons in semiconductor microcavities. These electrically neutral bosons coexist with charged electrons and holes. In the presence of magnetic fields, the charged particles are bound to their cyclotron orbits, while the neutral exciton-polaritons move freely. We demonstrate how magnetic fields affect dramatically the phase diagram of mixed Bose-Fermi systems, switching between fermionic lasing, incoherent emission and bosonic lasing regimes in planar and pillar microcavities with optical and electrical pumping. We collected and analyzed the data taken on pillar and planar microcavity structures at continuous wave and pulsed optical excitation as well as injecting electrons and holes electronically. Our results evidence the transition from a Bose gas to a Fermi liquid mediated by magnetic fields and light-matter coupling.}, language = {en} } @article{KimZhangWangetal.2016, author = {Kim, Seonghoon and Zhang, Bo and Wang, Zhaorong and Fischer, Julian and Brodbeck, Sebastian and Kamp, Martin and Schneider, Christian and H{\"o}fling, Sven and Deng, Hui}, title = {Coherent Polariton Laser}, series = {Physical Review X}, volume = {6}, journal = {Physical Review X}, number = {011026}, doi = {10.1103/PhysRevX.6.011026}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166597}, year = {2016}, abstract = {The semiconductor polariton laser promises a new source of coherent light, which, compared to conventional semiconductor photon lasers, has input-energy threshold orders of magnitude lower. However, intensity stability, a defining feature of a coherent state, has remained poor. Intensity noise many times the shot noise of a coherent state has persisted, attributed to multiple mechanisms that are difficult to separate in conventional polariton systems. The large intensity noise, in turn, limits the phase coherence. Thus, the capability of the polariton laser as a source of coherence light is limited. Here, we demonstrate a polariton laser with shot-noise-limited intensity stability, as expected from a fully coherent state. This stability is achieved by using an optical cavity with high mode selectivity to enforce single-mode lasing, suppress condensate depletion, and establish gain saturation. Moreover, the absence of spurious intensity fluctuations enables the measurement of a transition from exponential to Gaussian decay of the phase coherence of the polariton laser. It suggests large self-interaction energies in the polariton condensate, exceeding the laser bandwidth. Such strong interactions are unique to matter-wave lasers and important for nonlinear polariton devices. The results will guide future development of polariton lasers and nonlinear polariton devices.}, language = {en} } @article{RedlichLingnauHolzingeretal.2016, author = {Redlich, Christoph and Lingnau, Benjamin and Holzinger, Steffen and Schlottmann, Elisabeth and Kreinberg, S{\"o}ren and Schneider, Christian and Kamp, Martin and H{\"o}fling, Sven and Wolters, Janik and Reitzenstein, Stephan and L{\"u}dge, Kathy}, title = {Mode-switching induced super-thermal bunching in quantum-dot microlasers}, series = {New Journal of Physics}, volume = {18}, journal = {New Journal of Physics}, number = {063011}, doi = {10.1088/1367-2630/18/6/063011}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166286}, year = {2016}, abstract = {The super-thermal photon bunching in quantum-dot (QD) micropillar lasers is investigated both experimentally and theoretically via simulations driven by dynamic considerations. Using stochastic multi-mode rate equations we obtain very good agreement between experiment and theory in terms of intensity profiles and intensity-correlation properties of the examined QD micro-laser's emission. Further investigations of the time-dependent emission show that super-thermal photon bunching occurs due to irregular mode-switching events in the bimodal lasers. Our bifurcation analysis reveals that these switchings find their origin in an underlying bistability, such that spontaneous emission noise is able to effectively perturb the two competing modes in a small parameter region. We thus ascribe the observed high photon correlation to dynamical multistabilities rather than quantum mechanical correlations.}, language = {en} } @article{NitscheKimRoumposetal.2016, author = {Nitsche, Wolfgang H. and Kim, Na Young and Roumpos, Georgios and Schneider, Christian and H{\"o}fling, Sven and Forchel, Alfred and Yamamoto, Yoshihisa}, title = {Spatial correlation of two-dimensional bosonic multimode condensates}, series = {Physical Review A}, volume = {93}, journal = {Physical Review A}, number = {5}, doi = {10.1103/PhysRevA.93.053622}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188897}, pages = {53622}, year = {2016}, abstract = {The Berezinskii-Kosterlitz-Thouless (BKT) theorem predicts that two-dimensional bosonic condensates exhibit quasi-long-range order which is characterized by a slow decay of the spatial coherence. However previous measurements on exciton-polariton condensates revealed that their spatial coherence can decay faster than allowed under the BKT theory, and different theoretical explanations have already been proposed. Through theoretical and experimental study of exciton-polariton condensates, we show that the fast decay of the coherence can be explained through the simultaneous presence of multiple modes in the condensate.}, language = {en} } @article{LundtKlembtCherotchenkoetal.2016, author = {Lundt, Nils and Klembt, Sebastian and Cherotchenko, Evgeniia and Betzold, Simon and Iff, Oliver and Nalitov, Anton V. and Klaas, Martin and Dietrich, Christof P. and Kavokin, Alexey V. and H{\"o}fling, Sven and Schneider, Christian}, title = {Room-temperature Tamm-plasmon exciton-polaritons with a WSe\(_{2}\) monolayer}, series = {Nature Communications}, volume = {7}, journal = {Nature Communications}, doi = {10.1038/ncomms13328}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169470}, year = {2016}, abstract = {Solid-state cavity quantum electrodynamics is a rapidly advancing field, which explores the frontiers of light-matter coupling. Metal-based approaches are of particular interest in this field, as they carry the potential to squeeze optical modes to spaces significantly below the diffraction limit. Transition metal dichalcogenides are ideally suited as the active material in cavity quantum electrodynamics, as they interact strongly with light at the ultimate monolayer limit. Here, we implement a Tamm-plasmon-polariton structure and study the coupling to a monolayer of WSe\(_{2}\), hosting highly stable excitons. Exciton-polariton formation at room temperature is manifested in the characteristic energy-momentum dispersion relation studied in photoluminescence, featuring an anti-crossing between the exciton and photon modes with a Rabi-splitting of 23.5 meV. Creating polaritonic quasiparticles in monolithic, compact architectures with atomic monolayers under ambient conditions is a crucial step towards the exploration of nonlinearities, macroscopic coherence and advanced spinor physics with novel, low-mass bosons.}, language = {en} } @phdthesis{Schneider2011, author = {Schneider, Christian}, title = {Konzepte zur skalierbaren Realisierung von effizienten, halbleiterbasierten Einzelphotonenquellen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-73506}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2011}, abstract = {Dem Einsatz niederdimensionaler Nanostrukturen als optisch aktives Medium wird enormes Potential vorausgesagt sowohl in den klassischen optoelektronischen Bauteilen (wie z.B. Halbleiterlasern) als auch in optischen Bauteilen der n{\"a}achsten Generation (z.B. Einzelphotonenquellen oder Quellen verschr{\"a}nkter Photonenpaare). Dennoch konnten sich quantenpunktbasierte Halbleiterlaser, abgesehen von einigen wenigen Ausnahmen (QDLaser inc.), im industriellen Maßstab bisher nicht gegen Bauelemente mit h{\"o}herdimensionalen Quantenfilmen als optisch aktivem Element durchsetzen. Deshalb scheint der Einsatz von Quantenpunkten (QPen) in nichtklassischen Lichtquellen gegenw{\"a}rtig vielversprechender. Um jedoch solche Bauteile bis zur letztendlichen Marktreife zu bringen, m{\"u}ssen neben der starken Unterdr{\"u}ckung von Multiphotonenemission noch wesentliche Grundvoraussetzungen erf{\"u}llt werden: In dieser Arbeit wurden grundlegende Studien durchgef{\"u}hrt, welche insbesondere dem Fortschritt und den Problemen der Effizienz, des elektrischen Betriebs und der Skalierbaren Herstellung der Photonenqullen dienen sollte. Zum Einen wurden hierf{\"u}r elektrisch betriebene Einzelphotonenquellen basierend auf gekoppelten QP-Mikroresonatoren realisiert und de ren Bauteileffizienz gezielt optimiert, wobei konventionelle selbstorganisierte InAs-QPe als aktives Medium eingesetzt wurden. F{\"u}r die skalierbare Integration einzelner QPe in Mikroresonatoren wurde des Weiteren das gesteuerte QP-Wachstum auf vorstrukturierten Substraten optimiert und auf diese Art ortskontrollierte QPe in Bauteile integriert. F{\"u}r die Realisierung hocheffizienter, elektrisch gepumpter inzelphotonenquellen wurde zun{\"a}chst das Wachstum von bin{\"a}ren InAs-QPen im Stranski-Krastanov-Modus optimiert und deren optische Eigenschaften im Detail untersucht. Durch das Einbringen einer Schicht von Siliziumatomen nahe der QP-Schicht konnten die Emitter negativ geladen werden und der helle Trionenzustand der QPe als energetischer Eigenzustand des Systems zur effizienten Extraktion einzelner Photonen ausgenutzt werden. Durch die Integration dieser geladenen QPe in elektrisch kontaktierte, auf Braggspiegel basierte Mikrot{\"u}rmchen konnten Einzelphotonenquellen realisiert werden, in denen gezielt Licht-Materie- Wechselwirkungseffekte zur Steigerung der Bauteileffizienz ausgenutzt wurden. Basierend auf theoretischen {\"U}berlegungen wurde die Schichtstruktur soweit optimiert, dass letztendlich experimentell eine elektrisch gepumpte Einzelphotonenquelle mit einer Photonenemissionsrate von 47 MHz sowie einer zuvor unerreichten Bauteileffizienz von 34 \% im Regime der schwachen Licht-Materie-Kopplung demonstriert werden konnte. Da Effekte der Licht-Materie-Wechselwirkung zwischen QP und Resonator neben der spektralen Resonanz ebenfalls von der relativen Position von Resonator und QP zueinander abh{\"a}ngen, ist eine Kombination von positionierten QPen und Bauteilausrichtung nahezu unumg¨anglich f{\"u}r die skalierbare, deterministische Herstellung von Systemen aus perfekt angeordnetem Emitter und Resonator. Deshalb wurden bestehende Konzepte zum geordneten Wachstum von QPen weiterentwickelt: Hierbei wurde geordnetes InAs-QP-Wachstum mit Perioden realisiert, die vergleichbare Abmessungen wie optische Resonatoren aufweisen, also Nukleationsperioden zwischen 500 nm und 4 μm. Durch ein genaues Anpassen der Wachstums- und Prozessbedingungen konnte des Weiteren die Bildung von QP-Molek{\"u}len auf den Nukleationspl{\"a}tzen nahezu unterdr{\"u}ckt beziehungsweise gesteuert werden. Durch eine systematische Optimierung der optischen Eigenschaften der QPe konnten Emitter mit Einzelquantenpunktlinienbreiten um 100 μeV realisiert werden, was eine Grundvoraussetzung zur Studie ausgepr{\"a}gter Licht-Materie-Wechselwirkungseffekte in Mikroresonatoren darstellt. Letztendlich konnten durch die Integration derartiger QPe in optisch sowie elektrisch betriebene Mikroresonatoren erstmals Bauteile realisiert werden, welche einige der prinzipiellen, an eine Einzelphotonenquelle gestellten Anforderungen erf{\"u}llen. Insbesondere konnten deutliche Signaturen der schwachen Licht-Materie-Kopplung einzelner positionierter QPe in photonische Kristallresonatoren, Mikroscheibenresonatoren sowie Mikrot{\"u}rmchenresonatoren festgestellt werden. Dar{\"u}berhinaus konnte an einem spektral resonanten System aus einem positionierten QP und der Grundmode eines Mikrot{\"u}rmchenresonators eindeutig Einzelphotonenemission unter optischer Anregung demonstriert werden. Ebenfalls konnten Mikrot{\"u}rmchenresonatoren mit integrierten positionierten QPen erstmals elektrisch betrieben werden und somit die Grundvoraussetzung f{\"u}r eine der skalierbaren Herstellung effizienter Einzelphotonenquellen geschaffen werden.}, subject = {Einzelphotonenemission}, language = {de} } @article{AmthorWeissenseelFischeretal.2014, author = {Amthor, Matthias and Weißenseel, Sebastian and Fischer, Julian and Kamp, Martin and Schneider, Christian and H{\"o}fling, Sven}, title = {Electro-optical switching between polariton and cavity lasing in an InGaAs quantum well microcavity}, doi = {10.1364/OE.22.031146}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-111130}, year = {2014}, abstract = {We report on the condensation of microcavity exciton polaritons under optical excitation in a microcavity with four embedded InGaAs quantum wells. The polariton laser is characterized by a distinct nonlinearity in the input-output-characteristics, which is accompanied by a drop of the emission linewidth indicating temporal coherence and a characteristic persisting emission blueshift with increased particle density. The temporal coherence of the device at threshold is underlined by a characteristic drop of the second order coherence function to a value close to 1. Furthermore an external electric field is used to switch between polariton regime, polariton condensate and photon lasing.}, language = {en} }