Counterposed phase velocity and energy-transport velocity vectors in a dielectric-magnetic uniaxial medium

When a plane wave is launched from a plane surface in a linear, homogenous, dielectric-magnetic, uniaxial medium, we show that its phase velocity and the energy-transport velocity vectors can be counterposed (i.e., lie on different sides of the surface normal) under certain circumstances.Comment: 3 figure

The limits and extension of transformation optics

We explore an apparent limitation of transformation optics, namely that a given transformation induces polarization-dependent impedance gradients that might lead to scattering. This observation must be reconciled with the idea that the transformation optics algorithm is `exact', and leads to perfect morphing of the electromagnetic field without inducing scattering. We also discuss the role of curvature in transformation optics, showing that the conventional algorithm is nothing other than an interesting re-representation of flat Cartesian (Minkowskian) space (spacetime), without any curvature. However, we also consider possible extensions to transformation optics, to schemes that embrace curvature, and include so-called anholonomic transformations. We also show that the conventional spatial transformation optics algorithm can locally be described by six numbers

Due Process, Free Expression, and the Administrative State

The first Part of this Article will explore the theoretical foundations of procedural due process, focusing particularly on the essential due process requirement of a neutral adjudicator. We will follow that discussion with an analysis of the extent to which administrative adjudication of constitutional challenges to its regulatory authority or decisions satisfies the demands of procedural due process. After concluding that administrative regulators categorically fail to satisfy the requirements of due process, at least in the context of constitutional challenges to their regulatory authority, we will explain why the availability of post–administrative judicial review cannot cure the constitutional defect in administrative adjudication of First Amendment challenges to its regulatory authority. Finally, we will consider the extent to which modern administrative procedure authorizes the process that we deem constitutionally essential to enable the subject of administrative regulation to present its First Amendment challenge at a meaningful point in the process

Reverse Circular Bragg Phenomenon

The axial propagation of circularly polarized light in an optically active structurally chiral medium is exactly solved via full electromagnetic analysis. Some symmetries of the system's characteristic matrix reveal new insights, which are confirmed by coupled wave theory. For extreme values of chirality, now accessible via metamaterials, a reverse circular Bragg resonance arises in the negative refraction regime where handedness reversal of counterpart modes occurs. A condition is identified under which optical activity offsets structural chirality, rendering the medium simply birefringent.Comment: 14 pages, 6 figure

The negative index of refraction demystified

We study electromagnetic wave propagation in mediums in which the effective relative permittivity and the effective relative permeability are allowed to take any value in the upper half of the complex plane. A general condition is derived for the phase velocity to be oppositely directed to the power flow. That extends the recently studied case of propagation in mediums for which the relative permittivity and relative permeability are both simultaneously negative, to include dissipation as well. An illustrative case study demonstrates that in general the spectrum divides into five distinct regions.Comment: 5 pages, 4 figure