  We describe a new technology for the fabrication of inexpensive high-quality
mirrors. We begin by chemically producing a large number of metallic
nanoparticles coated with organic ligands. The particles are then spread on a
liquid substrate where they self-assemble to give optical quality reflective
surfaces. Since liquid surfaces can be modified with a variety of means (e.g.
rotation, electromagnetic fields), this opens the possibility of making a new
class of versatile and inexpensive optical elements that can have complex
shapes which can be modified within short time scales. Interferometric
measurements show optical quality surfaces. We have obtained reflectivity
curves that show 80% peak reflectivities.We are confident that we can improve
the reflectivity curves, for theoretical models predict higher values. We
expect that nanoengineered liquid mirrors should be useful for scientific and
engineering applications. The technology is interesting for large optics, such
as large rotating parabolic mirrors, because of its low cost. Furthermore,
because the surfaces of ferrofluids can be shaped with magnetic fields, one can
generate complex, time varying surfaces difficult to make with conventional
techniques.
