Finally a holograph you can touch..wow! Even in Star Wars when r2d2 projected the message to Luke you couldn’t touch it. Here is more on how it is done:
We present a method of rendering aerial and volumetric graphics using femtosecond lasers. A high-intensity laser excites a physical matter to emit light at an arbitrary 3D position. Popular applications can then be explored especially since plasma induced by a femtosecond laser is safer than that generated by a nanosecond laser. There are two methods of rendering graphics with a femtosecond laser in air: Producing holograms using spatial light modulation technology, and scanning of a laser beam by a galvano mirror.
Let’s check it out on video on the next page