The purpose of this work was to study the rectangular dielectric waveguide and its transitions to metalwaveguide at millimeter wavelengths. The thesis reviews different dielectric waveguiding structures, theiranalysis methods and their transitions to the metal waveguide. In this thesis work the analysis methods andtransitions are further developed. The main results of this work are:...

Power-dependent switching between the interacting modes of nonlinear dual-core (two-waveguide) couplers has attracted a great deal of interest during the past several years (see, for example, Synder et al.1 for a review of various physically important situations). In the theoretical papers2 -4 it has been demonstrated that three-waveguide nonlinear directional couplers offer some distinct advan...

fluids for various industrial applications because of their excellent thermal performance. this study analytically and experimentally examines the effects of nanoparticle dispersion on the entropy generation of eg–al2o3 nanofluid flows through a helical pipe as a heat exchanger under constant wall heat flux thermal boundary condition in laminar regime. it is found that adding nanoparticles impr...

We prove detailed analysis of a waveguide-based Schottky barrier photodetector (SBPD) where a thin silicide film is put on the top of a silicon-on-insulator (SOI) channel waveguide to absorb light propagating along the waveguide. Taking both the confinement factor of light absorption and the wall scanning induced gain of the photoexcited carriers into account, an optimized silicide thickness is...

A generalized equivalent circuit model for waveguide transverse slots is proposed for the efficient analysis of waveguide transitions and waveguide slot antennas and slot-excited antennas. The transverse slots on the broad and end waveguide walls analyzed in this paper are decomposed into three structures: two apertures and an auxiliary waveguide section. The slot aperture in the host waveguide...

We demonstrate propagation losses of less than 0.8 dB/microm in a metal slot waveguide on silicon with a predicted confinement substantially below the optical wavelength (approximately 1.55 microm). We also show compact and efficient coupling of the high-confinement metal slot waveguide with a standard silicon dielectric waveguide with a coupling efficiency of approximately 2.5 dB per facet.

We demonstrate a fundamental limitation in the force enhancement in simple waveguide-resonator geometry. We also show that the all-optical analog to electromagnetically induced transparency, as observed in a waveguideresonator geometry, can be used to drastically enhance waveguide-resonator optical force, significantly beyond what one can achieve in principle in conventional waveguide-resonator...

Conventional metallic waveguides have several major advantages, including low propagation losses and high power transmissions in the microwave frequency range. One disadvantage of metallic waveguides is that the propagation frequency band is limited at frequencies above the cutoff frequency fc. The usable frequency range is therefore restricted to fc < f < 2fc, because the TE20 mode can exist i...

This study numerically investigated heat transfer and fluid flow characteristics in a novel cylindrical heat sink with helical minichannels for the laminar flow of fluid with temperature-dependent properties. A finite volume method was employed to obtain the solution of governing equations. The effects of helical angle, channel aspect ratio, and Reynolds number, which were regarded as main para...

Helical coil heat exchangers are widely used in industrial applications ranging fromcryogenic processes, air-conditioning, and nuclear reactors to waste heat recovery due totheir compact size and high heat transfer coefficient. In this kind of heat exchangers, flowand heat transfer are complicated. This paper reports a numerical investigation of theinfluence of different parameters such as coil...