Ever since the innovation of laser, humans have long dreamt of shape-preserving light beams that could propagate robustly without broadening and distortion - even through turbulent media.
Ideally, one might achieve that goal using adaptive optics, diffraction-free beams such as Airy beams, or optical solitons. But complicated or unrealistic design requirements often make such techniques impractical for free-space applications.
Scientists from the Aerospace Information Research Institute (AIR) under the Chinese Academy of Sciences have found that the effect of air turbulence on laser beam was caused by introducing random transverse wave vectors. Based on this idea, they proposed a method to construct a special laser field that can eliminate transverse wave vectors during propagation to reduce the effect of air turbulence.
To demonstrate the validity of this method, the research team generated a pin-like optical beam and adopted it to propagate through air turbulence over a kilometer distance for the first time. Compared with the longest propagation distance of Bessel or Airy beams in the world (meters level), this method has improved the propagation distance up to three orders longer. Meantime, the production efficiency reached more than 90% (Fig. 1).
The method and technology are expected to offer a new approach to reduce the air turbulence effect to laser beam, and thereby improving the working performance of some laser systems such as laser communication and laser detection, especially when air turbulence is unavoidable.
The study was first published at the Conference on Lasers and Electro-Optics (CLEO) on May 5, 2019, and was fully published in the journal of Applied Physics Letters-Photonics.
It was on the list of "30 exciting peer-reviewed optics researches" that had emerged around the world in 2019, according to news on the annual highlights special issue recently released by the Optical Society of America (OSA).
OSA's annual highlights special issue was established in 1990, and it will select 30 most exciting research results from all over the world each year.
Fig. 1. Left: Artist’s illustration of generation of a shape-preserving pin-like beam from a single engineered phase mask and its propagation through atmospheric turbulence. Right: A Gaussian beam, propagating across 1 km in an open field, spreads and fluctuates dramatically (top), while the main lobe intensity of a pin-like beam (bottom) remains localized under the same propagation conditions. (Image by AIR)
The research team led by Shanghai Institute of Optics and Fine Mechanics, together with East China Normal University and Nanjing University of Aeronautics and Astronautics, has recently demonstrated single-mode lasing with low threshold, highly linear polarization degree ...
Ultrafast vector beams have wide applications in photochemistry, biology and physics. Recently, researchers at Shanghai Institute of Optics and Fine Mechanics (SIOM) generated novel multicolor concentric annular ultrafast vector beams (MUCAU-VB) based on cascaded four-wav...
86-10-68597521 (day)
86-10-68597289 (night)
86-10-68511095 (day)
86-10-68512458 (night)
cas_en@cas.cn
52 Sanlihe Rd., Xicheng District,
Beijing, China (100864)
Copyright © 2002 - Chinese Academy of Sciences
