Laser-induced plasma displays ionize air molecules to create glowing points of light. Japanese researchers have created a laser plasma display that is safe to touch. It uses femtosecond lasers, which create a pulse duration so minuscule that it doesn't result in any appreciable skin damage unless fired at the same spot at one shot per millisecond for a duration of 2,000 milliseconds. Touching the plasma produces a physical sensation, as if the light has a physical substance. The displays are still very small, but researchers suggest that it is possible to scale them with different optical devices. A video explaining the system and showing holograms generated by the display being touched is available in the article.