Using an old Chinese trick For the first time, researchers have used liquid crystals to create a “magic” window, a transparent device that creates a latent image when light shines on it. This technology is based on a very old light trick. Discuss u003d “Engineers created a “magic” liquid crystal window” Engineers created a “magic” window of liquid crystals liquid crystal window />
Thousands of years ago, craftsmen in China and Japan made bronze mirrors that looked like an ordinary flat mirror, but when exposed to direct sunlight, they formed a different image. It wasn't until the early 20th century that scientists realized how these devices worked: the light cast on the back of the mirror created small vibrations on the surface that formed an image.
the window appears perfectly flat to the naked eye, but it actually has small changes that create an image in response to light,” says team leader Felix Hufnagel of the University of Ottawa.
Liquid crystals are materials that can flow like a normal liquid, but have molecules that can be oriented like a solid crystal. In the new work, the researchers used a Pancharatnam-Berry Optical Element (PBOE), which is a liquid crystal device that operates on a principle called the Pancharatnam-Berry phase. By changing the orientation of the liquid crystal molecules in this device, the researchers were able to change the properties of the light passing through the device, pixel by pixel.