Touchable Holograms

Japanese researchers have developed the world’s first aerial hologram that can be physically touched and manipulated. It’s created using infrared laser light that’s precisely focused to ionize air molecules at the focal point and generate a flash of bluish-white plasma in midair.

Now, anyone familiar with plasma might ask, “Isn’t that dangerously hot?” and the answer would be, “Yes” but only if it’s generated at rates of two hundred thousand flashes per second, or thereabouts. When the bursts of light are shortened from nanoseconds to femtoseconds (quadrillionths of a second) the plasma is actually safe to touch. And when it comes into contact with skin, ionization creates tiny shock waves across the skin surface that results in a tingling sensation which feels somewhat like touching sandpaper. It also generates bright flashes of light that could be useful as a visual cue for video tracking or interactive holograms. The researchers envision future applications to include aerial markers for roads and runways or immersive holographic experiences in theaters and stadiums.