The paper gives a new method for analyzing planar discontinuities in rectangular waveguides. The method consists of a re-expansion of the normal modes in the two ducts at the junction plane into a system of functions accounting for the velocity singularities at the corner points. As the new expansion has an exponential convergence, only a few terms have to be considered for obtaining the soluti...

Experimental studies of the conductance properties of split-gate field-effect transistors have evidenced quantum wave guide effects for electron propagation through such structures.‘-3 Since then, a number of studies in such structures have been reported which have shown effects associated with resonant tunneling through impurities,4 superlattice effects due to a periodic grating,5 and single e...

in this paper, effects of the structural parameters on the optical characteristics of an add-drop filter, consisting of two straight waveguides and a micro-ring resonator (mrr), have been investigated. in this research, effects of mrr radius, the width of mrr and waveguide and the gap between mrr and waveguide, on free spectral range (fsr) and coupling coefficient have been studied. it is found...

in this article, the effect of cells' radius on the behavior of wavelength switching optical filter andthe effect of the radius of the optical filters' key characteristics such as wavelength resonance onan optical filter based on photonic crystals, have been investigated. currently, the most commonapplied mechanism for designing optical filter based on photonic crystals is using twomechanisms s...

in this paper, a resonant slotted waveguide array antenna with circular boundary has been designed and simulated for mono-pulse airborne radar applications. the antenna parameters are:11% bandwidth in x-band (8.6-9.6ghz),vswr < 2, 38dbi directivity, sidelobes level of - 20db and 3-db beam-widths of 2.1degree. to design this antenna, it is divided into short sections (sub-arrays) each with a uni...

The prime focus of this chapter is a hollow optical waveguide for integrated optics. Starting with a review of various novel hollow waveguide structures, physics and technology of tunable hollow waveguide have been presented with theory and experiments. With the flexible structure of hollow waveguide, a number of tunable optical functions can be realized; some of them are presented in the chapt...

In this paper, we propose a robust motion estimation algorithm using uncalibrated 3D motion model considering depth discontinuity. Most of the previous direct motion estimation algorithms with 3D motion model compute the depth value through the local smoothing, which result in erroneous results at depth discontinuity. In this paper, we overcome this problem at depth discontinuity by adding disc...

We demonstrate the feasibility of the process for fabricating a single-mode waveguide and a large-core multimode waveguide aligned vertically on the same substrate. Using this process, we propose and demonstrate a filter that drops optical signal propagating in a single-mode waveguide to a multimode waveguide in the specific wavelength interval by a long-period grating. We use perfluorocyclobut...

We demonstrate dynamical near-complete inversion switching of a two-level quantum dot driven by picosecond optical pulses in a bimodal photonic band gap PBG waveguide at microwatt power levels. This is enabled by a sharp steplike discontinuity in the local electromagnetic density of states LDOS provided by a cutoff in one of the two waveguide modes. The atomic Bloch vector equations in this col...

in this paper, the output power behavior of the wave-guide cw-co2 laser versus efficient parameters of laser performance was investigated. the output power variation versus the discharge current, the pressure and the gas mixture ratio was studied and optimized. the maximum output powers of 6 and 14.5 w were respectively obtained at operating pressures 78 and 50 mbar in two tubes of 3 mm same di...