  In this report, we achieved total transmission and reflection in a slab of
zero index materials with defect(s). By controlling the defect's radius and
dielectric constant, we can obtain total transmission and reflection of EM
wave. The zero index materials, in this report, stand for materials with
permittivity and permeability which are simultaneously equal to zero or so
called matched impedance zero index materials. Along with theoretical
calculations and simulation demonstrations, we also discuss about some possible
applications for the proposed structure such as shielding or cloaking an object
without restricting its view. We also suggest a way to control total
transmission and reflection actively by using tunable refractive index
materials such as liquid crystal and BST. The physics behind those phenomena is
attributed to intrinsic properties of zero index materials: constant field
inside zero index slab.
