Concealment by uniform motion

The perceived lateral position of a transmitted beam, upon propagating through a slab made of homogeneous, isotropic, dielectric material at an oblique angle, can be controlled through varying the velocity of the slab. In particular, by judiciously selecting the slab velocity, the transmitted beam can emerge from the slab with no lateral shift in position. Thereby, a degree of concealment can be achieved. This concealment is explored in numerical calculations based on a 2D Gaussian beam

Determination of constitutive and morphological parameters of columnar thin films by inverse homogenization

A dielectric columnar thin film (CTF), characterized macroscopically by a relative permittivity dyadic, was investigated theoretically with the assumption that, on the nanoscale, it is an assembly of parallel, identical, elongated ellipsoidal inclusions made of an isotropic dielectric material that has a different refractive index from the bulk material that was evaporated to fabricate the CTF. The inverse Bruggeman homogenization formalism was developed in order to estimate the refractive index of the deposited material, one of the two shape factors of the ellipsoidal inclusions, and the volume fraction occupied by the deposited material, from a knowledge of relative permittivity dyadic of the CTF. A modified Newton--Raphson technique was implemented to solve the inverse Bruggeman equations. Numerical studies revealed how the three nanoscale parameters of CTFs vary as functions of the vapour incidence angle