A laser light beam passes in between a loudspeaker-reflector array that develops a grating of air. The laser beam interacts with this grating and is deflected without contact. Using an unique approach, beams of laser light can be deflected utilizing air alone. An invisible grating made only of air is not just immune to damage from the laser light, however it likewise preserves the original quality of the beam, reports the interdisciplinary research study group in the journal Nature Photonics. The deflection of light straight into ambient air, which has actually already been demonstrated, opens up promising applications, particularly as a quick switch for high-power lasers.
With the aid of unique speakers, the scientists shape a pattern of dense and less thick locations in the air, forming a striped grating. In a manner that resembles how differential air densities bend the light in the Earths atmosphere, the density pattern takes on the function of an optical grating that alters the direction of the laser beam.
” However, deflecting light by diffraction grating allows far more precise control of the laser light compared to deflection in the Earths atmosphere,” says Schrödel. “The properties of the optical grating are affected by the frequency and intensity– to put it simply, the volume– of the acoustic waves.”
Lab Results and Potential
In the preliminary laboratory tests, a strong infrared laser pulse might be redirected in this method with a performance of 50 percent. Considerably higher efficiencies should be possible in the future, according to numerical designs. For the first test, the researchers had to turn their unique speakers way up.
” We are moving at a sound level of about 140 decibels, which corresponds to a jet engine a few meters away,” discusses scientist Christoph Heyl from DESY and the Helmholtz Institute Jena, who is leading the research study task. “Fortunately, we remain in the ultrasound range, which our ears dont pick up.”
The team sees fantastic possible in the method for high-performance optics. In their experiments, the researchers utilized an infrared laser pulse with a peak power of 20 gigawatts, which corresponds to the power of around 2 billion LED bulbs. Lasers of this and even greater power classes are used, for instance, for product processing, in combination research study, or for the most recent particle accelerators.
” In this power range, the material properties of mirrors, lenses, and prisms substantially restrict their usage, and such optical components are quickly harmed by strong laser beams in practice,” discusses Heyl. “In addition, the quality of the laser beam suffers. On the other hand, weve managed to deflect laser beams in a quality-preserving way without contact.”
Further Applications and Insights
The concept of acoustic control of laser light in gases is not limited to the generation of optical gratings, the researchers emphasize. It can most likely also be transferred to other optical components such as waveguides and lenses.
” Weve been considering this technique for a long time and rapidly recognized that extreme sound levels are required. Initially, these seemed technically unfeasible,” explains Heyl. “However, we did not quit and finally discovered a service with the support of researchers at the Technical University of Darmstadt as well as the business Inoson. We tried out our technique with normal air. Next, for example, we will also utilize other gases in order to use other wavelengths and other optical homes and geometries.”
The deflection of light straight into ambient air, which has actually currently been demonstrated, opens up promising applications, particularly as a fast switch for high-power lasers. “The potential of contactless control of light and its extension to other applications can currently just be thought of,” discusses Heyl. “Modern optics is based nearly specifically on the interaction of light with strong matter. Our method opens a totally new direction.”
Recommendation: “Acousto-optic modulation of gigawatt-scale laser pulses in ambient air” by Yannick Schrödel, Claas Hartmann, Jiaan Zheng, Tino Lang, Max Steudel, Matthias Rutsch, Sarper H. Salman, Martin Kellert, Mikhail Pergament, Thomas Hahn-Jose, Sven Suppelt, Jan Helge Dörsam, Anne Harth, Wim P. Leemans, Franz X. Kärtner, Ingmar Hartl, Mario Kupnik and Christoph M. Heyl, 2 October 2023, Nature Photonics.DOI: 10.1038/ s41566-023-01304-y.
Researchers from the Technical University of Darmstadt, Aalen University of Applied Sciences, Universität Hamburg, Inoson GmbH in St. Ingbert, the Helmholtz Institute Jena, and DESY were involved in the work.
A laser light beam passes between a loudspeaker-reflector selection that develops a grating of air. The laser beam engages with this grating and is deflected without contact. Credit: Science Communication Lab for DESY
Ingenious concept alters the instructions of laser light with the aid of sound waves.
Utilizing an unique technique, beams of laser light can be deflected using air alone. An unnoticeable grating made only of air is not only immune to damage from the laser light, however it also protects the original quality of the beam, reports the interdisciplinary research group in the journal Nature Photonics. The scientists have gotten a patent for their method.
Strategy and Principle
The ingenious strategy uses sound waves in order to regulate the air in the area where the laser beam is passing. “Weve produced an optical grating with the aid of acoustic density waves,” explains first author Yannick Schrödel, a Ph.D. student at DESY and Helmholtz Institute Jena.