Laser

A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation". The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light coherently. Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances (collimation), enabling applications such as laser pointers. Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum, i.e., they can emit a single color of light. Temporal coherence can be used to produce pulses of light as short as a femtosecond.

  • “MuReA“ Provides Quick and Large-Scale Laser Applications

    The multi remote system of the Fraunhofer IWS Dresden processes large areas by means of laser radiation and atmospheric pressure plasma. © Fraunhofer IWS Dresden

    The Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS developed the novel remote system concept (MuReA) for quick, flexible and efficient laser processing tasks. IWS scientists combined laser remote systems, spindle drives and high performance beam sources with each other. As a result, this novel laser system enables large-scale, flexible and quick processing tasks for materials such as aluminum, stainless steel as well as fiber reinforced polymers. Working areas of up to one square meter can be processed at a laser beam speed of up to 10 meters per second. In particular, the automotive and the aerospace industry will benefit from possible applications.

  • 26.1 % Record Efficiency for p-Type Crystalline Si Solar Cells

    Monocrystalline silicon solar cell with POLO-contacts for both polarities on the solar cell rear side. In the foreground the rear side of seven solar cells processed on one wafer can be seen. ISFH

    The Institute for Solar Energy Research Hameln (ISFH) and Leibniz Universität Hannover have developed a crystalline silicon solar cell with an independently confirmed efficiency of (26.10 +/- 0.31 %) under one sun. This is a world record for p-type Si material, which currently covers ~90% of the world photovoltaic market. The record cell uses a passivating electron-selective n+ type polysilicon on oxide (POLO) junction and a hole-selective p+ type POLO junction. It is the high selectivity of theses junctions that allow these high efficiencies. As an important step towards industrialization, laser ablation is used for the contact opening process.

  • 2nd Conference on Laser Polishing LaP 2016 in Aachen

    Remelting a thin surface layer is an effective way to laser polish many metals and glasses. The focus of the two-day LaP conference, which will be held at the Fraunhofer Institute for Laser technology ILT in Aachen on April 26 and 27, 2016, will be on presentations and practical demonstrations profiling the various techniques.

  • 3D Images of Cancer Cells in the Body: Medical Physicists from Halle Present new Method

    A picture of a tumor (green) generated with the newly developed technique. Jan Laufer

    Making tumour cells glow: Medical physicists at Martin Luther University Halle-Wittenberg (MLU) have developed a new method that can generate detailed three-dimensional images of the body's interior. This can be used to more closely investigate the development of cancer cells in the body. The research group presents its findings in "Communication Physics", a journal published by the Nature Publishing Group.

  • A Fine-tuned Laser Welds More Effectively

    Cardiac pacemakers are usually housed in a titanium housing that is welded together from two parts. Empa has optimized the frequency of the working laser so that no black edges appear during welding, which would reduce the value of the medical product. Image: istockphoto

    Using laser technology Empa scientists optimized a technique to weld the electronics of implantable pacemakers and defibrillators into a titanium case. The medtech company Medtronic is now using the method worldwide to produce these devices. In Tolochenaz (Canton of Vaud) the US medtech company Medtronic produces one out of five heart pacemakers available on the global market and one out of four defibrillators. The electronics of these implantable devic-es are housed in titanium cases, which thus far were welded hermetically with a solid state flash laser. However, the lasers are high-maintenance and often the source of irregularities. Moreover, they require water cooling and take up a lot of space.

  • A laser for divers

    Laser cutting of sheet piling under water. Photo: LZH

    Working under water is personnel- and time-intensive. The Laser Zentrum Hannover e.V. (LZH) is therefore working on developing a laser-based, automated process for cutting sheet piling under water, together with the Institute of Materials Science of the Leibniz Universität Hannover. Sheet piling protects fortified shore areas, or can be used to dry out these areas if repairs are necessary. If the sheet piling must be dismantled, divers must cut the walls into smaller pieces using a cutting torch. Normally, a diver can cut about 20 meters a day, which corresponds to a speed of about 0.07 meters per minute. In the project LuWaPro, scientists at the LZH have now developed a process which uses a disc laser for torch cutting. The divers thus only carries out a supervisory role. The process can be used to separate the metal sheets, which are usually 10 mm thick for sheet piling, at speeds of up to 0.9 m/min.

  • A New Knob to Control and Create Higher Harmonics in Solids

    When exciting crystals such as silicon by an intense elliptically or circularly polarized light pulse (red), circularly polarized higher harmonics (green & blue) can be generated. Nicolas Tancogne-Dejean + Joerg M. Harms, MPSD

    Scientists at the MPSD and CFEL have demonstrated the possibility of using a new knob to control and optimize the generation of high-order harmonics in bulk materials, one of the most important physical processes for generating high-energy photons and for the ultrafast manipulation of information.

  • 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 signal boost for molecular microscopy

    A signal boost for molecular microscopy | Schematic illustration of the experiment. Graphic: MPQ, Laser Spectroscopy Division

    Cavity-enhanced Raman-scattering reveals information on structure and properties of carbon nanotubes. The inherently weak signals are amplified by using special micro cavities as resonator, giving a general boost to Raman spectroscopy as a whole.

  • Additive Manufacturing: Budget-friendly Retrofit of Module for Wire-based Laser Deposition Welding

    Processing head "LMD-W-20-L" for wire-based laser deposition welding. Graphic: Fraunhofer IPT

    When economic or safety considerations rule out the use of powder materials in additive manufacturing, the option of wire-feed laser deposition welding resents itself. The Fraunhofer Institute for Production Technology IPT in Aachen has developed a smart laser module for wire deposition welding, which can easily be integrated within existing process chains, handling systems or machine tools. The engineers from Aachen will be unveiling the LMD-W-20-L module for the first time to the visitors from industry at Formnext, the Fair for Additive Technologies in Frankfurt/Main, Hall 3, Booth E70, 13-16 November 2018.

  • ADIR Project: Lasers Recover Valuable Materials

    Contactless exposure and unsoldering of circuit board components by means of laser radiation in a recycling process of the “ADIR” project.

    Taking electronic devices apart that are no longer in use to recover valuable raw materials – this is an essential aspect of the future of urban mining. The Fraunhofer-Gesellschaft is taking a pioneering role internationally in the EU project “ADIR - Next generation urban mining – Automated disassembly, separation and recovery of valuable materials from electronic equipment”. Launched in September 2015, this project is scheduled to run until 2019. It comprises nine project partners from four countries, who are researching how strategically important materials from old cell phones and printed circuit boards can be retrieved and recycled.

  • An International Team of Physicists Discovered a Coherent Amplification Effect in Laser Excited Dielectrics

    Copyright: Uni Kassel

    An international team of physicists from the University of Kassel, led by Prof. Thomas Baumert, and the University of Aarhus, led by Prof. Peter Balling, discovered that ultra-short laser pulses are amplified in a laser excited piece of glass. This amplification, similar to a classical laser, is directed and of coherent nature. By utilizing theoretical models and simulations, the researchers were able to understand and reproduce the multi-step process leading to the “Laser Amplification in Excited Dielectrics” (short: LADIE) named effect. Their results were published online in the well-known research journal Nature Physics.

  • Auch das Deuteron gibt Rätsel auf: Proton und Deuteron doch kleiner als gedacht?

    Auch das Deuteron gibt Rätsel auf Proton und Deuteron doch kleiner als gedacht picture1 | Karsten Schuhmann und Aldo Antognini an dem Lasersystem, das für die Laserspektroskopie eingesetzt wurde. Foto: Paul Scherrer Institut/Markus Fischer

    Das Deuteron – ein Atomkern aus nur einem Proton und einem Neutron – ist deutlich kleiner als bislang gedacht. Zu diesem Ergebnis kommt eine internationale Forschungsgruppe, die Experimente am Paul Scherrer Institut PSI durchgeführt hat. Dies passt zu einer Studie aus dem Jahr 2010, bei dem dieselbe Forschungsgruppe das Proton vermessen und damit das "Rätsel um den Protonradius" begründet hatte. Nun gibt die Deuterongrösse ein analoges Rätsel auf. Womöglich wird dies zu einer Anpassung der Rydbergkonstante führen. Die Experimente fanden an der weltweit leistungsstärksten Myonenquelle am PSI statt, wo die Forschenden mittels Laserspektroskopie sogenanntes myonisches Deuterium vermassen.

  • Blick in den Anfang des Regenbogens

    Die intensivsten und schnellsten optischen Signale – Blitze aus einem Ultrakurzpulslaser – sind heute das Präzisionswerkzeug der Grundlagenforschung, Automobilindustrie und Augenheilkunde. Ihr Licht unterscheidet sich grundlegend von üblichen, einfarbigen Laserstrahlen: Es besteht aus einem Regenbogenspektrum, und je kürzer der Puls, desto reicher die Farben. Wissenschaftler der Universität Göttingen und der University of California in Los Angeles haben nun erstmals die Entstehung dieses „Regenbogens“ in Echtzeit und mit einer Bildrate von 90 Millionen Schnappschüssen pro Sekunde gefilmt.

  • Carbon Nanotubes Couple Light and Matter

    The formation of exciton-polaritons through strong light-matter coupling is a promising strategy for producing electrically pumped carbon-based lasers. Scientists from Heidelberg University and the University of St Andrews (Scotland) have now, for the first time, demonstrated this strong light-matter coupling in semiconducting carbon nanotubes. Figure: Arko Graf (Heidelberg University)

    Scientists from Heidelberg and St Andrews work on the basics of new light sources from organic semiconductors. With their research on nanomaterials for optoelectronics, scientists from Heidelberg University and the University of St Andrews (Scotland) have succeeded for the first time to demonstrate a strong interaction of light and matter in semiconducting carbon nanotubes. Such strong light-matter coupling is an important step towards realising new light sources, such as electrically pumped lasers based on organic semiconductors. They would be, amongst other things, important for applications in telecommunications. These results are the outcome of a cooperation between Prof. Dr Jana Zaumseil (Heidelberg) and Prof. Dr Malte Gather (St Andrews), and have been published in “Nature Communications”.

  • Care-O-bot® 4 celebrates its première as shopping assistant

    Paul, a member of the Care-O-bot® 4 robot family, has been greeting customers in Saturn-Markt Ingolstadt since the end of October 2016 and directing them towards their desired products. Source: Saturn

    In January 2015, Fraunhofer IPA presented a prototype of the “Care-O-bot® 4” service robot. The charming helper is now proving its worth in the real world. “Paul” the robot has been greeting customers in Saturn-Markt Ingolstadt since the end of October 2016 and directing them towards their desired products. Care-O-bot 4®, alias Paul, approaches Saturn customers and welcomes them to the store. If they ask him about a certain product, he accompanies the customer to the department and points them in the direction of the relevant shelf. As he indulges in small talk about the weather or another subject, Paul turns out to be a most charming contact partner. However, he prefers to leave actual customer service to his human colleagues.

  • Chemical Reactions in the Light of Ultrashort X-ray Pulses from Free-electron Lasers

    Ultrashort X-ray pulses (pink) ionize neon gas in the center of the ring. An infrared laser (orange) deflects the electrons (blue) on their way to the detectors. Image: Terry Anderson / SLAC National Accelerator Laboratory

    Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

  • Corrective glass for mass spectrometry imaging

    Custom-built laser source for mass spectrometry imaging: By means of the improved LAESI technique the surface of this coarse piece of savoy cabbage can now be chemically analyzed. Benjamin Bartels / Max Planck Institute for Chemical Ecology

    Researchers at the Max Planck Institute for Chemical Ecology in Jena, Germany, have now improved mass spectrometry imaging in such a way that the distribution of molecules can also be visualized on rippled, hairy, bulgy or coarse surfaces. The source of the laser-based technique was custom-built to accommodate the topography of non-flat samples. By employing a distances sensor, a height profile of the surface is recorded before the actual chemical imaging. The new tool can be used for answering ecological questions from a new perspective.

  • Cost efficient Diode Lasers for Industrial Applications

    The »Brilliant Industrial Diode Lasers« (BRIDLE) project has been finished successfully after 42 months of intense research activities. BRIDLE was made possible by funding from the European Commission. The seven project partners finished their work at the end of February 2016. The project was coordinated by »DILAS Diodenlaser GmbH« (Germany), the project partners are located in Germany, UK, Switzerland, France and Finland. BRIDLE targeted a major increase in the brightness achievable in direct diode laser systems, based on advances in diode laser and beam -combining technology. Throughout, the highest conversion was sought as was compatibility with low cost, volume manufacture.

  • Das MPQ päsentiert den Original-Laser

    Prof. Theodore Maiman (Foto: K. Maiman)

    Im Jahr 1960 begann eine neue Ära der Technologiegeschichte. Theodore Maiman stellte den ers-ten funktionierenden Laser der Öffentlichkeit vor. Ein kleines Gerät bestehend aus einer Blitzlampe, einem Rubinkristall und einer Hülse aus Metall. Maimans erster Laser hat die Jahrzehnte überdauert. Jetzt ist das Original im Foyer des Max-Planck Instituts für Quantenoptik (MPQ) in Garching b. München in einer kleinen Ausstellung zu sehen. Zusammen mit dem Laser präsentiert das MPQ das Original-Laborbuch von Theodore Maiman mit seinen bahnbrechenden Skizzen des Geräts. Die Ausstellung ist ab dem 12. Dezember 2016 kostenlos zu besichtigen am Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str.1, 85748 Garching; täglich von 9 bis 17 Uhr. Journalisten sind herzlich zur Ausstellungseröffnung am 12. Dezember 2016 um 15 Uhr im Foyer des MPQ eingeladen.