Holograms are pretty cool and a team of Japanese researchers have managed to make small floating holograms that react when touched. Check out the clip to learn more.
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. The holograms and workspace of the system proposed here occupy a volume of up to 1 cm^3; however, this size is scalable depending on the optical devices and their setup. This paper provides details of the principles, system setup, and experimental evaluation, and discussions on scalability, design space, and applications of this system. We tested two laser sources: an adjustable (30-100 fs) laser which projects up to 1,000 pulses per second at energy up to 7 mJ per pulse, and a 269-fs laser which projects up to 200,000 pulses per second at an energy up to 50 ¹J per pulse. We confirmed that the spatiotemporal resolution of volumetric displays, implemented with these laser sources, is 4,000 and 200,000 dots per second. Although we focus on laser-induced plasma in air, the discussion presented here is also applicable to other rendering principles such as fluorescence and microbubble in solid/liquid materials.
Fairy Lights in Femtoseconds: Aerial and Volumetric Graphics Rendered by Focused Femtosecond Laser Combined with Computational Holographic Fields
Yoichi Ochiai*, Kota Kumagai**, Takayuki Hoshi***, Jun Rekimoto****, Satoshi Hasegawa**, and Yoshio Hayasaki**
*University of Tsukuba ** Utsunomiya University ***Nagoya Institute of Technology **** The University of Tokyo and Sony CSL