Fairy Lights in Femtoseconds

Abstract

We present a method of rendering aerial and volumetric graphics using femtosecond lasers. A high-intensity laser excites physical matter to emit light at an arbitrary three-dimensional position. Popular applications can thus be explored, especially because plasma induced by a femtosecond laser is less harmful 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 article provides details of the principles, system setup, and experimental evaluation, and discusses the scalability, design space, and applications of this system. We tested two laser sources: an adjustable (30--100fs) laser that projects up to 1,000 pulses/s at an energy of up to 7mJ/pulse and a 269fs laser that projects up to 200,000 pulses/s at an energy of up to 50μJ/pulse. We confirmed that the spatiotemporal resolution of volumetric displays implemented using these laser sources is 4,000 and 200,000 dots/s, respectively. Although we focus on laser-induced plasma in air, the discussion presented here is also applicable to other rendering principles such as fluorescence and microbubbles in solid or liquid materials.

A Model of Spatial Directness in Interactive Visualization

“…In addition, the data volume is arranged with respect to a virtual camera such that the human observer sees a projection of the optical properties, governed by the DVR process. Typically, this projection is shown on a regular monoscopic PC monitor, but alternatives such as stereoscopic rendering (using one projection per eye; e. g., [23], [85]) and true 3D rendering (for which no algorithmic projection and composition are needed; e. g., [32], [63]) exist as well. For all these cases, however, the observers interpret what they see to understand the depiction as a representation of the 3D data, and to explore it accordingly.…”

“…In case of stereoscopic rendering, the 3D position can also be taken from a tracked 3D interaction device, held either in front of (e. g., CAVE [23]) or behind (e. g., HMD [14]) the stereoscopic projection. Alternatively, in the same case, the hands of the interacting person can be tracked in 3D space (e. g., [63]).…”

SonicSpray: A Technique to Reconfigure Permeable Mid-Air Displays

“…Our technique can act as an alternative to the bulky robotic arm that is used in the drawing work. SonicSPray also can be used to create small display features as in Fairy Light of Femtoseconds laser [20], while retaining a safe to touch interface.…”

Star Wars-style 3D images created from single speck of foam

“…In 2016, Ochiai's team adapted the plasma technique, using a lower-energy, shorter-pulse laser to make images that are safe to touch 5 . At a few millimetres across, the images are much smaller than the Kimura team's.…”