  Starting from optical nihility media (ONM), we design several intriguing
devices with transformation optics method in two dimensions, such as a wave
splitter, a concave lens, a field rotator, a concentrator and an invisibility
cloak. The extreme anisotropic property of ONM hinders the fabrication of these
devices, which could be effectively realized by simplified materials with
Fabry-P\'erot resonances (FPs) at discrete frequencies. Moreover, we propose a
reduced version of simplified materials with FPs to construct a concentrator
and a rotator, which is feasible in experimental fabrications. The simulations
of total scattering cross sections confirm their functionalities.
