Japanese researchers have developed 3D plasma displays with haptic feedback, or in other words, touchable 3D holograms. Previous attempts at high resolution holograms were too dangerous to touch. Volunteers who have touched the new holograms described the sensation as being similar to a static shock. The team from the University of Tsukuba’s Digital Nature Group tried several methods before finding the right laser and perfecting the timing.
Ultimately, they created the touchable holograms by using a high-intensity laser called a femtosecond laser to excite molecules and cause them to emit visible light in the air. The researchers have reported that when they used other lasers, the resulting light burned through leather. The femtosecond laser, however, sends miniature bursts as short a 30 to 270 quadrillionths of a second. This produces tiny points of plasma called voxels, which were quieter and safer than the plasma that is generated by a slower nanosecond laser. By combining the ultrafast laser with a spatial light modulator, a mirror, and a Galvano scanner for precise targeting, the researchers created shapes up to 1 cubic centimeter with a resolution of up to 200,000 dots-per-second.
The researchers have said that the plasma they generated is safe enough to eventually be incorporated into our daily lives. However, at this point the holograms are limited to a laboratory setting because generating them requires large, expensive equipment. The team plans to present their work in Los Angeles this August at an international conference on computer graphics and interactive techniques called SIGGRAPH2015.