A phase sensitive measurement technique that permits the simultaneous determination
of two independent thermal properties of thin dielectric films is presented. Applying the technique results in a film's thermal diffusivity and effusivity, from which the thermal conductivity and specific heat can be calculated. The technique involves measuring a specimen's front...
Raw material costs and limited material availability and quality have created
significant interest in and opportunities for the application of nondestructive
evaluation techniques to improve wood processing technologies. The incentives come
from the desire to 1) manufacture the highest valued product, 2) conserve the
amount of raw material used, 3)...
In this thesis the concept of inhomogeneous
dielectrics is demonstrated for various optical coating
applications. Compositionally-varying silicon oxynitride
(SiON) dielectric layers, with the refractive index
varying as a function of position, are grown by computer-controlled
plasma-enhanced chemical vapor deposition
(PECVD) using silane, nitrogen, and nitrous oxide reactant
gases. Compositionally graded...
The drying of wood is required in most forest products
manufacturing operations. Depending on the wood species,
dimensions, drying temperatures, and drying duration, the
amount of emissions and energy consumption can greatly affect
the operating cost, environment, and quality of wood dried.
As such, the forest products industry continues to...
Dielectric waveguides are becoming important for their numerous
applications in integrated optics. The study of dielectric waveguides by analytical
techniques is not sufficient for many variations in waveguide shape, anisotropy,
and inhomogeneity commonly encountered in waveguide materials. This work
studies the finite element method as an accurate tool for the...
Local field effects on the dielectric properties of solids have
been studied for three-dimensional and two-dimensional crystals by
using two kinds of dipole models: an atomic dipole model in which
dipoles coincide with atom sites and a bond dipole model in which
dipoles are placed along bond directions. Local fields...
This work is concerned with the modeling and analysis of lossy planar dielectric
optical waveguides. Loss mechanisms which affect propagation characteristics are
reviewed, and various representations of the propagation constant in the lossy case
are defined. Waveguide structures which are susceptable to absorption and/or to
leakage loss, in particular silicon-based...
Multiport network functions, such as impedance matrix
parameters and scattering parameters, of general multiple
coupled slab waveguides are derived in terms of the normal
mode parameters of the system. These characteristic normal
mode parameters include the propagation constants, the
modal impedances, and the eigenvector matrices. It is
shown that the...