For The First Time, Researchers Have Successfully Used Air To Deflect A Laser!

Recently, researchers at the German Electron Synchrotron (DESY) Research Center announced that they are now able to deflect laser beams by using an invisible grating system made from air. The optical system is described as being made from ultrasound and will not be damaged by the laser (after all, it's just air), nor will it degrade the quality of the beam.
The team has applied for a patent for this new method, and a related paper was published in the journal Nature Photonics. It involves the use of a special loudspeaker, which allows the creation of air patterns of different densities. While the mass remains constant, the device is currently only 50 percent efficient, but the team believes these aspects can be further advanced in the future.
Yannick Schr?del, the first author of the aforementioned research paper and a doctoral student at DESY and the Helmholtz Institute in Jena, said in a statement that they have produced an optical grating based on acoustic density waves.
The innovative technique uses sound waves of 140 decibels (equivalent to the sound level of a jet engine a few meters away), but in the ultrasonic range so they are inaudible to the human ear. These sound waves form layers of varying density. The work was inspired by how light is bent by the Earth's atmosphere as it passes through layers of different densities.
"However, deflecting light through a diffraction grating allows for more precise control of the laser than deflection in the Earth's atmosphere." Schr?del explained that the properties of the grating are affected by the frequency and intensity of the sound waves.
In their experiments, the researchers used infrared laser pulses with a peak power of 20 GW - which is equivalent to about 2 billion LEDs, or the amount of energy needed to send 16.5 Droning cars back into the future. Due to their power characteristics, such lasers can be used to process materials, among other things.
"In this power range, the material properties of mirrors, lenses and prisms greatly limit their use, and these optics are easily damaged in practice by strong laser beams." Christoph Heyl, project leader, also from DESY and the Helmholtz Institute, adds, "In addition, the quality of the laser beam is also affected. In contrast, we have managed to deflect the laser beam in a way that preserves the quality without contact."
The DESY researchers mentioned that extreme sound levels were necessary for the study. Although initially extreme sound levels seemed technically unattainable, they eventually found a solution with the support of the researchers at the Technical University of Darmstadt and the company Inoson. The DESY team has now successfully combined the technology with ordinary air to produce relevant applications.
Now, the team has been able to create a grating system, but they believe they will also use other gases to apply to other wavelengths, or to produce other optical properties, optical structures - such as lenses and waveguides. And, it may even be possible to use different gases to interact with different types of lasers.
"The potential for non-contact control of light, and the other applications for which it can be extended, is currently only at the level of the imagination," says Heyl, adding that "modern optics is almost entirely based on the interaction of light with solid matter. Our approach opens up a whole new direction."