Experimental verification of negative refractive index materials using yttrium iron garnet

Left hand materials are composite medium which have simultaneously negative permittivity and permeability. The tradition methods to artificial fabricate left hand materials are static, so the experiment devices to verify them are relatively simple. A novel approach is presented to synthesize left hand materials with negative refractive index in microwave band by incorporating periodic metallic wire array into yttrium iron garnet applied by external magnetic field. The effective permeability of yttrium iron garnet and the effective permittivity of periodic metallic wire array are synchronously negative under certain external magnetic field. Theoretically investigation and simulations have been done to test its microwave transmission property and negative refractive character and prove that it is left hand material. In this paper, experiment devices to test the novel left hand material sample are depicted. Transmission experimental and prism experimental methods and results are revealed. To verify the magnetic tunable property of the sample, a set of magnetic field generator is designed, by which a tunable homogenous magnetic field can be obtained. The experiment steps using these designed devices are set forth in detail.