Researchers at Tianjin University (TJU) in northern China have reportedly made a breakthrough in holography based on optical metasurfaces, with experts saying the technology could greatly boost the efficiency of military reconnaissance.
The Beijing-based Science and Technology Daily reported that a research team in the university’s Center for Terahertz Waves had explored a new holographic imaging technique and realized reflective chiral holography for the first time.
Holography is the science and practice of making holograms, photographic recordings of a light field, rather than of an image formed by a lens, and are used to display a fully three-dimensional image of the holographed subject that can be seen without the aid of special glasses or other intermediate optics.
Terahertz waves, also known as submillimeter waves, are electromagnetic waves with strong penetrability and directionality but are safe for humans, and are at the frontier of electromagnetic sensing and imaging, according to the TJU team. The wave can be an alternative to X-rays for producing high resolution images of the interior of solid objects to complement with holographic technologies.
The Global Times cited military expert Song Zhongping as saying that using the metasurfaces material and terahertz waves, the updated holographic plate could exhibit an image with very accurate location, dimensions of an object being monitored and a slew of other information, which would in turn improve military reconnaissance.
Holographic plates with metasurfaces could also record more data and better reproduce the images than ordinary plates.
The metasurface plates can recognize different polarization states of light. This enables them to store more information and make fully independent holographic imaging.
If fully developed, the technology would bring a sharp leap forward in reconnaissance for the Chinese army, according to the research team, with applications such as hologram-like imaging and holographic sensors, a device that consists of a hologram embedded in a smart material that detects certain molecules or metabolites, such as gases, water content or metal ions.
Optical scientists at the University of Arizona funded by the Pentagon have already demonstrated what The New York Times called “actual moving holograms that are filmed in one spot and then projected and viewed in another spot” for instantaneous transmission of holographic maps in 3D, far better than the classic 2D “bird’s-eye view.”