Reflection terahertz time-domain spectroscopy for imaging and identifying concealed interfaces in insulated systems.

Polarization-resolved reflection spectroscopy enabled by a custom ultrahigh molecular weight polymer dove prism is used to identify spectral characteristics that manifest in the time domain at terahertz frequencies, which shows promise in combination with terahertz time-domain reference-free reflection imaging at a concealed interface. The method is used to produce 100×100 pixel images of an interface concealed by an ultrahigh molecular weight polymer using TE and TM polarized terahertz fields. The construction of material-specific image filters is guided by a theoretical reflection model by identifying reflection pulse characteristics unique to an interface.

Tunneling and reflection of an exciton incident upon a quantum heterostructure barrier.

We investigate, in one spatial dimension, the quantum mechanical tunneling of an exciton incident upon a heterostructure barrier. We model the relative motion eigenstates of the exciton using a form of the one-dimensional hydrogen atom which avoids difficulties previously associated with 1D hydrogenic states. We obtain probabilities of reflection and transmission using the method of variable transmission and reflection amplitudes.

Tomographic reconstruction of multiple in-line electron holograms of realistic objects.

In theoretical low energy electron point source microscopy, simulated holograms are made and used to reconstruct atomic clusters. In previous investigations, simple test clusters were used for convenience. In this paper we explore more realistic structures composed of a single type of atom such as diamond, graphite and Buckminsterfullerene--all of which consist of carbon atoms.

Iterative reconstruction of in-line electron holograms.

In low energy electron point source (LEEPS) microscopy, electrons emerge from a point source, propagate as spherical waves, and arrive at a screen. Some electrons scatter off an object, i.e.

Reconstruction of composite in-line electron holograms using a small emission cone.

We report a new method that gives atomic resolution in the reconstruction of simulated holograms in theoretical low energy electron point source (LEEPS) microscopy, and that uses a screen size that is commensurate with screen sizes used in experimental LEEPS. The method exploits the spherical symmetry in the electron waves emerging from the source. We compare holograms obtained by rotating the screen about an axis passing through the point source as opposed to rotating the atomic cluster in the opposite sense about the same axis.