There is now a global interest in the creation of creation of electromagnetic metamaterials. The substantive early work isfocused upon the GHz frequency range but almost immediately the desire to progress rapidly to the optical frequencyrange gathered momentum. This is a natural desire because many applications operate at optical frequencies but the THzrange is also important for a range of medical applications as well. The concepts that underpin the need formetamaterials, and their special properties, are explained in this article and why the creation of exotic, artificial,molecules is required to produce material behaviour beyond any performance that could naturally be expected. It will beshown that the major key lies in adding magnetic properties to special dielectric behaviour. This leads to composites thathave almost magical behaviour. This presentation will explore the current global experimental progress towards three-dimensional metamaterials and will explain, in a straightforward manner, the concept of negative refraction that isattracting such a lot of attention. The initial ideas, and even some of the early misconceptions, will be addressed andclearly illustrated in a manner that enhances any understanding of the conceptual structure will be expressed. It will beshown that even though negative refraction can be associated with both backward and forward waves, the novelmetamaterial concept is to associate backward wave phenomena with isotropic media, artificially endowed with negativepermittivity and permeability. The principle application shown here is to a nonlinear ring interferometer that is capableof sustaining arbitrarily thin solitons or "optical needles" that can also be managed by an external magnetic field.
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