ABSTRACT
Transformation optics generally needs gradient anisotropic meta-
materials with extreme material parameters for realization. For
applications in which a larger-frequency bandwidth is desired,
one possible route is to seek coordinate maps that can minimize
the generated index range and anisotropy. In this chapter, we
demonstrate quasiconformal map (QCM) as a useful tool for
minimizing anisotropy, while the index range can be further
minimized by avoiding sharp corners in boundaries. We will give
examples with both analytic and numerical approaches and show
the corresponding map generation can be simplified by taking an
electrostatic analogy. We will also discuss its extension to acoustic
and elastic waves and investigate an elastodynamic carpet cloak.
These considerations are useful in a wide class of applications such
as invisibility cloaks and optimized integrated optical devices at the
optical wavelengths.
