Engineers and applied physicists have laid the foundations for a new type of "plug and play" laser -- the Raman injection laser -- and in the process, several key innovations in laser technology. The device combines the advantages of nonlinear optical devices and semiconductor injection lasers with a compact design, and may one day lead to wide-ranging applications in imaging and detection.
Published in the Feb. 24th issue of Nature, the proof of concept model was developed by Mariano Troccoli, Ertugrul Cubukcu and Federico Capasso of the Harvard University Division of Engineering and Applied Sciences; Alexey Belyanin of Texas A&M University; and Deborah L. Sivco and Alfred Y. Cho of Bell Laboratories, Lucent Technologies. The finding was supported in part by Texas A&Ms Telecommunications and Informatics Task Force Initiative.
Conventional Raman lasers depend on a fundamental phenomenon in physics called the Raman effect-the change in the frequency of monochromatic light (such as a laser) when it passes through a substance. When light from an intense exciting laser beam, known as the "pump," deflects off the molecules of certain materials, some of the incident photons lose part of their energy. As a result, a secondary laser beam with a frequency shifted from that of the exciting laser emerges from the material.
Keith Randall | EurekAlert!
Fraunhofer ISE Pushes World Record for Multicrystalline Silicon Solar Cells to 22.3 Percent
25.09.2017 | Fraunhofer-Institut für Solare Energiesysteme ISE
Producing electricity during flight
20.09.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
25.09.2017 | Power and Electrical Engineering
25.09.2017 | Health and Medicine
25.09.2017 | Physics and Astronomy