Cloak enough to cover visible objects

A team in UK recently fabricated a cloak that works under green light to make optical delusions [http://arxiv.org/ftp/arxiv/papers/1012/1012.2783.pdf]. This cloak is large and able to cover an object as large as 10mm^3. The physics is governed by Maxwell's equations. The substance is calcite, which has anisotropic optical properties.