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 uJ 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.