Optics

  • First quantum photonic circuit with electrically driven light source

    Graphic representation of part of a chip, showing with photon source, detector and waveguides Illustration: Münster University/Wolfram Pernice

    Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

  • Humboldt Fellowship for research on tunable optical surfaces for Terahertz technology

    Dr. Corey Shemelya. Thomas Koziel/TU Kaiserslautern

    U.S. scientist Dr. Corey Shemelya has recently started a research stay at the University of Kaiserslautern in the form of a fellowship granted by the Alexander von Humboldt Foundation. Dr. Shemelya is studying structured optical surfaces which hold potential applications in communication technology and Terahertz imaging, e.g. body scanning equipment for airport safety. Shemelya is working in conjunction with the Terahertz Technology Laboratory of Professor Marco Rahm at the Department of Electrical and Computer Engineering and the State Research Center for Optical and Material Sciences (OPTIMAS).

  • Matter-antimatter symmetry confirmed with precision record

    Sketch of the experimental setup used at CERN for the determination of the antiproton-to-electron mass ratio. Graphic: Masaki Hori

    CERN experiment sets precision record in the measurement of the antiproton to electron mass ratio using a new innovative cooling technique. According to the Standard Model of elementary particle physics, to each particle exists an antiparticle that is supposed to behave exactly the same way. Thus, “anti-people” in an “anti-world” would observe the same laws of physics, or make the same experiences in general, as we do. This postulate is, however, difficult to prove, since it is almost impossible to perform measurements on antimatter: whenever an antiparticle meets is matter-counterpart, both particles annihilate, accompanied by the creation of energy.

  • Quantum Particles Form Droplets

    Quantum droplets may preserve their form in absence of external confinement because of quantum effects. IQOQI/Harald Ritsch

    In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

  • Scientists shrink electron gun to matchbox size

    A miniature electron gun driven by Terahertz radiation: An ultraviolett pulse (blue) back-illuminates the gun photocathode, producing a high density electron bunch inside the gun. The bunch is immediately accelerated by ultra-intense single cycle Terahertz pulses to energies approaching one kilo-electronvolt (keV). These high-field optically-driven electron guns can be utilized for ultrafast electron diffraction or injected into the accelerators for X-ray light sources. Credit: W. Ronny Huang, CFEL/DESY/MIT

    Terahertz technology has the potential to enable new applications.In a multi-national effort, an interdisciplinary team of researchers from DESY and the Massachusetts Institute of Technology (MIT) has built a new kind of electron gun that is just about the size of a matchbox. Electron guns are used in science to generate high-quality beams of electrons for the investigation of various materials, from biomolecules to superconductors. They are also the electron source for linear particle accelerators driving X-ray free-electron lasers.

  • The nanostructured cloak of invisibility

    Substrate with 450 nm nanopillars (left) compared to an unstructured reference (right). The top set of images were taken at an observation angle of 0°, the bottom set of images at 30°. © Zhaolu Diao

    Most lenses, objectives, eyeglass lenses, and lasers come with an anti-reflective coating. Unfortunately, this coating works optimally only within a narrow wavelength range. Scientists at the Max Planck Institute for Intelligent Systems in Stuttgart have now introduced an alternative technology. Instead of coating a surface, they manipulate the surface itself. By comparison with conventional procedures, this provides the desired anti-reflective effect across a wider wavelength range. But more than this, it largely increases the light transmittance through surfaces.

  • Ultrashort and Extremely Precise

    Innsbruck physicists observe a surprising quantum effect when short light pulses interact with matter. Patrick Maurer

    A group of theoretical physicists headed by Oriol Romero-Isart from the Institute for Quantum Optics and Quantum Information and the University of Innsbruck observes a surprising quantum effect when short light pulses interact with matter. In the future, this effect may be used for developing a completely new type of far-field light nanoscopes.