Power combining of TM surface waves by a planar active-lens amplifier is the subject of this paper. An amplifier gain of 11 dB at 8.25 GHz with a 3-dB bandwidth of 0.65 GHz has been demonstrated. Gain is measured from input to output connector to facilitate comparisons with more conventional amplifiers. Measurements of output power versus input power are also presented. The amplifier behaved in...

In this paper a new optical channel drop filter (CDF) based on two dimensional (2-D) photonic crystals (PhC) with hexagonal shaped structure is proposed and numerically demonstrated by using the finite-difference-time-domain (FDTD) and plane-wave-expansion (PWE) techniques. Photonic crystals (PhCs) are artificial dielectric nanostructure materials in which a periodic modulation of the material ...

Although surface polariton modes supported by finite-width interfaces can guide electromagnetic energy in three dimensions, we demonstrate for the first time to our knowledge that such modes can be modeled by the solutions of two-dimensional dielectric slab waveguides. An approximate model is derived by a ray-optics interpretation that is consistent with previous investigations of the Fresnel r...

Thermal noise in multilayer optical coatings may not only limit the sensitivity of future gravitational wave detectors in their most sensitive frequency band but is also a major impediment for experiments that aim to reach the standard quantum limit or to cool mechanical systems to their quantum ground state. Here, we present the experimental realization and characterization of a cavity coupler...

in this paper, a recurrent fuzzy-neural network (rfnn) controller with neural network identifier in direct control model is designed to control the speed and exhaust temperature of the gas turbine in a combined cycle power plant. since the turbine operation in combined cycle unit is considered, speed and exhaust temperature of the gas turbine should be simultaneously controlled by fuel command ...

An 11.4 GHz standing wave Dielectric Loaded Accelerating (DLA) structure was recently developed. The structure is designed to achieve a 120 MV/m gradient powered by a 10 MW 200 ns rf pulse from the X-band Magnicon at the Naval Research Laboratory (NRL). The structure uses on-axis rf coupling, which helps to localize the maximum EM fields within the dielectric region. Bench testing shows excelle...

A new and useful type of optical resonator has been proposed based on the principles of chaos [1]. The asymmetric resonant cavity (ARC) is an extension of the concept of spherical or cylindrical dielectric resonators which have high-Q ”whispering gallery” (WG) modes trapped by total internal reflection [2]. In the ARC such a cylinder or sphere is deformed substantially but in a smooth and conve...

We have developed a technique for photothermal displacement spectroscopy that is potentially orders of magnitude more sensitive than conventional methods. We use a single Fabry-Perot resonator to enhance both the intensity of the pump beam and the sensitivity of the probe beam. The result is an enhancement of the response of the instrument by a factor proportional to the square of the finesse o...

We consider an oblate Bose-Einstein condensate of heteronuclear polar molecules in a weak applied electric field. This system supports a rich quasiparticle spectrum that plays a critical role in determining its bulk dielectric properties. In particular, in sufficiently weak fields the system undergoes a polarization wave rotonization, leading to the development of textured electronic structure ...

Chung, Haejun MSECE, Purdue University, December 2013. Time Domain Simulation With Novel Photovoltaic Materials. Major Professor: Peter Bermel. Thin-film silicon-based solar cells have operated far from the Shockley-Queisser limit in all experiments to date. Novel light-trapping structures, however, may help address this limitation. Finite-difference time domain simulation methods offer the pot...