Engineering the electric and magnetic dispersive responses of artificial media

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ENGINEERING THE ELECTRIC AND MAGNETIC RESPONSES OF ARTIFICIAL MEDIA Much of our modern conveniences and technological advances are the consequence of our ability to control and modify the behaviour of naturally occurring materials and to manufacture artificial materials with properties otherwise absent in the natural world.  In electromagnetic theory, the material behaviours and responses are often classified according to the so called "dispersive effects."  Depending on the researcher's area of interest and expertise, he or she may use different descriptions such as various delays (for example, phase delay, group delay, group delay dispersion, and so on), indices, or velocities to characterize the same dispersive effects.   Despite these different terminologies, we may note that fundamental and important relations exist among the various delays, indices, and velocities.  The title of this proposal then conveys our desire to manage, manipulate, and compensate the aforementioned various delays, indices, or velocities - the dispersive effects - by synthesizing artificial materials and utilizing their novel properties.   This ability to manufacture artificial materials with properties not found in the natural systems has allowed us to demonstrate some very unusual and counter intuitive phenomena; for example, the demonstration of negative index of refraction and the observation of negative or superluminal group delays and group velocities.   In the first case a beam of light seems to be refracted opposite to what is commonly expected, and in the second case, the peak (or envelope) of an electromagnetic pulse appears at the output terminal before the peak (or envelope) of the input pulse has reached the input terminal.  Despite their counter intuitive appearances, both effects are causal and in complete agreement with our fundamental physical laws.   In the present proposal, we intend to further investigate the theoretical and practical implications of these effects in the context of Dispersion Engineering paradigm.