Light

  • A Nano-Roundabout for Light

    Functional principle of a nano-roundabout.  © TU Wien

    At TU Wien, it was possible to create a nanoscale optical element that regulates the flow of light particles at the intersection of two glass fibers like a roundabout. A single atom was used to control the light paths. Just like in normal road traffic, crossings are indispensable in optical signal processing. In order to avoid collisions, a clear traffic rule is required. A new method has now been developed at TU Wien to provide such a rule for light signals. For this purpose, the two glass fibers were coupled at their intersection point to an optical resonator, in which the light circulates and behaves as in a roundabout. The direction of circulation is defined by a single atom coupled to the resonator. The atom also ensures that the light always leaves the roundabout at the next exit. This rule is still valid even if the light consists merely of individual photons. Such a roundabout will consequently be installed in integrated optical chips – an important step for optical signal processing.

  • A Quantum Low Pass for Photons

    Illustration of the two-photon blockade. Top: Irradiated by a laser pulse a single atom in free space can absorb and emit only one photon at a time, without constraints on the direction of the photons. Middle: A system consisting of a cavity can absorb and emit an unlimited number of photons. Below: In case of the strongly coupled atom-cavity system the frequency of the laser light can be chosen such that the system can store and emit two photons at maximum. MPQ, Quantum Dynamics Division

    Physicists in Garching observe novel quantum effect that limits the number of emitted photons. The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called Poisson-distribution. There are, however, light sources with non-classical photon number distributions that can only be described by the laws of quantum mechanics. A well-known example is the single-photon source that may find application in quantum cryptography for secret key distribution or in quantum networks for connecting quantum memories and processors. However, for many applications in nonlinear quantum optics light pulses with a certain fixed number of photons, e.g. two, three or four, are highly desirable.

  • A quantum walk of photons

    An electron microscope image of a so-called micropillar with an integrated quantum dot that is capable of emitting single photons.  Photo: Chair for Applied Physics, University of Würzburg

    Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

    The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer. Therefore, it is expected to work out problems in the not too far future which are virtually impossible to solve by classical supercomputers. Physicists refer to this as "quantum computational supremacy".

  • ALGEN REVOLUTIONIEREN 3D-DRUCK VON ZELLEN

    Felix Krujatz erhält für seine Doktorarbeit auf dem Gebiet der Algenbiotechnologie den Nachwuchsförderpreis der Sächsischen Akademie der Wissenschaften. Kirsten Mann

    Wissenschaftler der TU Dresden gewinnt Nachwuchsförderpreis der Sächsischen Akademie der Wissenschaften / Algenbiotechnologie revolutioniert 3D-Bioprinting / weltweit erster 3D-gedruckter Bioreaktor mit OLEDS macht neue Untersuchungsmethoden möglich. Felix Krujatz, Wissenschaftlicher Mitarbeiter an der Fakultät Maschinenwesen der TU Dresden, erhält für seine Doktorarbeit „Entwicklung und Evaluierung neuer Bioreaktorkonzepte für phototrophe Mikroorganismen“ den Nachwuchsförderpreis der Sächsischen Akademie der Wissenschaften zu Leipzig. Seine Forschungsergebnisse enthalten mehrere Weltneuheiten auf dem Gebiet der Biotechnologie und können u.a. das Bioprinting menschlicher Zellen für regenerative Therapien revolutionieren sowie eine neue Generation von Bioreaktoren hervorbringen. Der Preis wird am 09. Dezember um 16:00 Uhr in Leipzig öffentlich verliehen.

  • Chiral Quantum Optics: A New Research Field with Bright Perspectives

    Surprising effect: directional emission of light  TU Wien

    Surprising direction-dependent effects emerge when light is guided in microscopic structures. This discovery shows promise for both classical and quantum information processing.

    Recently, surprising physical effects were observed using special microscopic waveguides for light. Such “photonic structures” currently are revolutionizing the fields of optics and photonics, and have opened up the new research area of “Chiral Quantum Optics”. Physicists from Copenhagen, Innsbruck, and Vienna, who are leading figures in this field, have now written an overview on the topic which just appeared in the scientific journal “Nature”.

  • Cholesterol important for signal transmission in cells

    CXCR4 receptor which belongs to a group known as G protein-coupled receptors. FAU/Rainer Böckmann

    Cholesterol can bind important molecules into pairs, enabling human cells to react to external signals. Researchers at Friedrich-Alexander University Erlangen-Nürnberg’s (FAU) Chair of Biotechnology have studied these processes in more detail using computer simulations. Their findings have now been published in the latest volume of the journal PLOS Computational Biology*. FAU researchers Kristyna Pluhackova and Stefan Gahbauer discovered that cholesterol strongly influences signal transmission in the body. Their study focused on the chemokine receptor CXCR4, which belong to a group known as G protein-coupled receptors (GPCRs). These receptors sense external stimuli such as light, hormones or sugar and pass these signals on to the interior of the cell which reacts to them. CXCR4 normally supports the human immune system. However, it also plays an important role in the formation of metastases and the penetration of HIV into the cell interior.

  • Flexible OLEDs glowing from first European open access pilot line

    Flexible OLED on plastic web. Fraunhofer FEP

    Fraunhofer FEP has extensive and long lasting expertise and know-how in operation of its R&D lines for manufacturing of OLED lighting devices. As one of the core team partners within the European pilot line project PI-SCALE Fraunhofer FEP presents first demonstrators of flexible OLED out from this project. The demonstrators represent results from first pilot line production within the PI-SCALE project at the IDW 23rd International Display Workshops in Fukuoka, Japan, from December 7 – 9, 2016 on 4th floor, booth no. 13.

  • Grenzen der optischen Mikroskopie überwinden

    Darstellung von gestreutem Licht. Copyright: Benjamin Judkewitz, Charité – Universitätsmedizin Berlin.

    ERC Starting Grant für interdisziplinäres Charité-Labor. Die Technik der optischen Mikroskopie hat wesentlich zur Begründung der Neurowissenschaften beigetragen. Aus der Forschung ist sie kaum wegzudenken. Allerdings: Bis heute bleibt die mikroskopische Bildgebung in lebenden Organismen auf Tiefen von weniger als einem Millimeter begrenzt. Der Grund dafür ist die Lichtstreuung. Diese Grenze aufzuheben und lebendes Gewebe in tieferen Schichten, beispielsweise in der Hirnrinde, sichtbar zu machen, das hat sich die Forschergruppe um Prof. Dr. Benjamin Judkewitz vorgenommen. In den kommenden fünf Jahren stehen dem Labor nun 1,49 Millionen Euro des Europäischen Forschungsrates (ERC) zur Verfügung.

  • Heart examinations: Miniature particle accelerator saves on contrast agents

    Prof. Franz Pfeiffer and PD Dr. Daniela Münzel at the miniature synchrotron Munich Compact Light Source (MuCLS). Heddergott / TUM

    The most prevalent method for obtaining images of clogged coronary vessels is coronary angiography. For some patients, however, the contrast agents used in this process can cause health problems. A team at the Technical University of Munich (TUM) has now demonstrated that the required quantity of these substances can be significantly reduced if monoenergetic X-rays from a miniature particle accelerator are used.

    Soft tissues such as organs and blood vessels are nearly impossible to examine in X-ray images. To detect a narrowing or other changes in coronary blood vessels, patients are therefore usually injected with an iodinated contrast agent.

  • How do cells move? Researchers in Münster investigate their mechanical features

    Fluorescent beads (green) in a one-day old zebrafish embryo. The beads injected at the one-cell stage were maintained within the embryos and did not affect their development. Credit: Hörner et al./Journal of Biophotonics

    Using an optical method, researchers at the Cells-in-Motion Cluster of Excellence have investigated the mechanical features of cells in living zebrafish embryos and manipulated, for the first time, several components in the cells simultaneously. The study appears in the Journal of Biophotonics.

    Cells form tissues or organs, migrate from place to place and in doing that their mechanical features and forces generated within them play a key role. Researchers at the Cells-in-Motion Cluster of Excellence at Münster University have now investigated the mechanical features of cells in living zebrafish embryos using the holographic optical tweezers-based method.

  • How photons change chemistry

    Photons in an optical cavity alter the properties of molecules, such as their binding length. Jörg M. Harms/MPSD

    The quantum nature of light does usually not play an important role when considering the chemical properties of atoms or moelcules. In an article published in the Proceedings of the National Academy of Sciences scientists from the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron-Laser Science (CFEL) in Hamburg show, however, that under certain conditions photons can strongly influence chemistry. These results indicate the possibility that chemical processes can be tailored by photons.

  • Individualized fiber components for the world market

    From the Science and Technology Park Hannover (WTH) to the world market: The FiberBridge Photonics GmbH manufactures fiber components and modules for laser and light guiding systems. FiberBridge Photonics GmbH

    On June 14th, 2017, Dr.-Ing. Thomas Theeg, scientist at the Laser Zentrum Hannover e.V. (LZH), founded the 18th spin-off company of the research institute. Specialized in custom glass fiber components, fiber modules and manufacturing systems for these components, the FiberBridge Photonics GmbH will be providing customers from research, production, telecommunications and medical technology with individualized products.

    Already in March 2016, the business idea had been awarded at the StartUp-Impuls ideas competition of the Sparkasse Hannover and the hannoverimpuls GmbH in the “Going Global” category. Furthermore, in November 2016, scientists of the LZH received funding through the EXIST research transfer program of the German Federal Ministry of Economic Affairs and Energy.

  • InLight study: insights into chemical processes using light

    “Throwing light into the process”: Determination of chemical parameters by optical measurement through a vessel wall. Fraunhofer ILT, Aachen, Germany.

    Optical process analytics – this fast and non-contact method of measuring chemical and physical parameters provides high-density information without the need to take samples. What’s more, it can be shrunk to a far smaller size and is easy to integrate into existing process lines. From its location in Aachen, Germany, the Fraunhofer Institute for Laser Technology led a consortium to analyze the future potential of this technique in cooperation with BAM and RWTH Aachen University. The purpose of the study, entitled “Inline process analytics with light – InLight” was to develop a technology roadmap and a detailed white paper that will be presented to a wider public in early 2017.

  • International Stir Caused by Unusual Study on Noble Gases

    Nobel gases are used as light sources in fluorescent tubes. Foto: thauwald-pictures/fotolia.com

    Experts acclaim the research findings of the team of authors from Bremen, Leipzig, Wuppertal and the USA as a scientific breakthrough in basic research. The world leading journal “Applied Chemistry” features the study on its cover page.

    Reactions with noble gases have long been a cause of fascination for chemists. The substances used as light sources in fluorescent tubes, for instance, are extremely slow to react in respect of their chemical reactions – they are therefore called “noble”. A newly published study in this area of basic research is currently causing quite a stir in expert circles.

  • Leibniz-IPHT Scientist Presents First Flexible Optical Tweezer in Nature Photonics

    Dynamic holographic optical tweezers (HOT) manipulation of eight particles in a rotating cube arrangement.Source: Nature Photonics (2017) doi:10.1038/s41566-017-0053-8. Photo: Leibniz-IPHT

    Tomáš Čižmár studies new methods to control light propagation in optical fibers. The scientist, who recently relocated from University of Dundee in Scotland to the Leibniz-Institute of Photonic Technology in Jena (Leibniz-IPHT), published an article about optical traps for medical diagnostics in the highly-cited journal Nature Photonics. Optical traps are tightly focused light beams that can be used to confine, manipulate and examine microscale objects such as cells or DNA. Tweezers made of light are not new. Due to their bulky optics, researchers so far could only manipulate and study biomolecules outside their natural environment on microscope slides. 

  • Lichtfernbedienung für die Reparatur von Materialien

    Durch Licht-Bestrahlung kann sich die intelligente Kunststoffbeschichtung gezielt selbst reparieren. Bild: Stefan Hecht

    Forscherteam unter Leitung der HU entwickelt intelligente Kunststoffbeschichtung, die sich durch Licht-Bestrahlung gezielt repariert. Muss ein stark beschädigter Alltagsgegenstand ausgewechselt werden, ist das zumeist umweltbelastend und teuer. Um dies in Zukunft zu vermeiden, arbeiten Forscher seit Jahren an der Entwicklung neuer Materialien, die Kratzer oder Risse reparieren können. Ein Team unter Leitung von Forschern der Humboldt-Universität zu Berlin (HU) hat nun erstmals Kunststoffbeschichtungen entwickelt, die mit Hilfe von Licht gezielt Beschädigungen heilen können. Die Ergebnisse ihrer Studie stellen sie in der Nature Communications vor.

  • Light-emitting bubbles captured in the wild

    Coloured sonoluminescence of xenon in concentrated sulfuric acid with dissolved sodium salt. University of Göttingen

    High-power ultrasound is used for cleaning surfaces or wastewater as well as for destroying kidney stones. These applications use a curious effect caused when ultrasound enters liquids: bubbles are generated and some emit light. At the University of Göttingen, physicists have imaged, for the first time, sonoluminescence flashes together with the bubbles in an ultrasonically driven bubble cloud. By high-speed video recording with up to 0.5 million images taken per second, light emitting bubbles can be identified and their shapes and oscillations analyzed. High-power ultrasound is used for cleaning surfaces or wastewater as well as for destroying kidney stones. These applications use a curious effect caused when ultrasound enters liquids: bubbles are generated that periodically grow and collapse.

  • Looking at complex light wave forms

    The electronic field moves in complex trajectories as a light pulse propagates. Graphics: Giuseppe Sansone

    Using a new method, researchers can see for the first time how weak electric fields evolve in time.

    For the first time an international research team under the direction of Prof. Dr. Giuseppe Sansone at the Institute of Physics at the University of Freiburg has been able to completely characterize the complex evolution of weak electric fields. The team just published its research findings in the scientific journal Nature Photonics.

  • LZH at the LASER World of Photonics 2017: Light for Innovation

    Are you facing challenges beyond the cutting edge? The LZH is your ideal partner at the LASER 2017.  Photo: LZH

    At this year's LASER – World of PHOTONICS in Munich from June 26th to June 29th, 2017, the Laser Zentrum Hannover e.V. (LZH) will be presenting the latest research results and services in hall A3 at stand 506. Popular monuments from the skyline of Hannover will be illustrating the core competencies of the LZH.

    The focus is on optical components and systems, optical production technologies as well as on industrial and biomedical optics. Among other things, the LZH will be presenting optics for special applications, compact lasers and the latest developments in the field of laser material processing and quality control.

  • LZH initiates an innovations network on optogenetics

    Electrophysiological investigation of an optogenetically altered neuron cell line. Photo: LZH

    Within the framework of the BMBF initiative “Innovation forums for small and medium-sized enterprises (SMEs)”, the Laser Zentrum Hannover e.V. (LZH) is striving to set up a nationwide network on optogenetics. This network will pool the competencies of the relevant research fields in order to unlock the potential of light-controllable biomolecules in combination with up-to-date light technology. Especially in the area of biomedical sciences, there are promising approaches for new treatment methods, for example for neurological diseases.