For generation of photons above 100 keV with a magnetic field strength in the range 0.2-0.5 Tesla, an undulator wavelength λu shorter than 5 mm may be needed with beam in the Advanced Photon Source (APS) storage ring. A microwave beam waveguide undulator system has been investigated for generation of such light. The waveguide structure consists of two parallel reflector surfaces that can be der...

We demonstrate sidewall gratings in an ultra-low-loss Si3N4 planar waveguide platform. Through proper geometrical design we can achieve coupling constant values between 13 and 310 cm(-1). The TE waveguide propagation loss over the range of 1540 to 1570 nm is below 5.5 dB/m.

In this Article dispersion characteristic of conventional optical waveguide with helical winding at core – cladding interface has been obtained. The model dispersion characteristics of optical waveguide with helical winding at core-cladding interface have been obtained for five different pitch angles. This paper includes dispersion characteristics of optical waveguide with helical winding, and ...

This paper extends a previously proposed method for designing filters simulating the dispersion phenomenon occurring in string instruments. In digital waveguide synthesis, the phenomenon is traditionally modeled by inserting an allpass filter to the string model feedback loop. In this paper, the concept of tunable dispersion filter design, which provides a closed-form formula to design a disper...

We have developed a powerful parallel genetic algorithm design tool for photonic crystal and waveguide structures. The tool employs a small-population-size genetic algorithm (microgenetic algorithm) for global optimization and a two-dimensional finite-difference time-domain method to rigorously design and optimize the performance of photonic devices. We discuss the implementation and performanc...

The Dielectric Resonator Antenna (DRA) is one of the efficient radiator which is used to achieve broadband and cost effective communication in wireless technology. The Substrate Integrated Waveguide (SIW) technology is the most assuring structure for implementation of circuits and components for millimeter wave and microwave applications. A design approach to improve the impedance bandwidth of ...

Design of high gain and high efficiency antennas is one of the key challenges in antenna engineering and especially in millimeter wave communication systems. Various types of planar waveguide arrays with series-fed traveling wave operation have been developed in Tokyo Tech with the special focus upon efficiency enhancement as well as reduction of fabrication cost. In this review, four kinds of ...

We propose a silicon Fabry–Perot planar waveguide modulator structure consisting of two Bragg reflectors to form the cavity. The Bragg reflectors are nanoscale trenches in the waveguide fabricated using electron beam lithography and reactive ion etching. Compared to conventional waveguide modulator designs, large modulation depth can be achieved with much smaller modulator length using high-fin...

1. Introduction Leaky-wave antennas based on an open-waveguide structure can become a candidate of millimeter-wave antennas. Since such a structure is already open, leakage is produced by introducing not a physical cut, but asymmetry of the structure. As a result, it supports a leaky mode (instead of a bound mode) and therefore radiates all along its length, possess flexibility in beamwidth and...