216 research outputs found
Stein: Impact of New Weapons Technology on International Law: Selected Aspects
A Review of Impact of New Weapons Technology on International Law: Selected Aspects by Eric Stei
Moskowitz: Human Rights and World Order. The Struggle for Human Rights in the United Nations
A Review of Human Rights and World Order. The Struggle for Human Rights in the United Nations. By Moses Moskowitz
Tunable, narrow-band, grating-assisted microring reflectors
Tunable, grating-assisted ring resonator based optical mirrors are analyzed and their characteristics numerically evaluated. Mode number selection rules are presented to aid mirror optimization for high, narrow-band reflection and efficient sidelobe suppression. Data is presented on tuning sensitivity, on the effect of coupling on bandwidth and reflection coefficient, and on the influence of waveguide and grating loss on mirror performance. Group delay in the presence of loss and circuit parameter variations is also treated.Publicad
Narrow-band, Bragg-grating-assisted microring reflectors: tunability, reflection loss and group delay
5 pages, 9 figures.-- Contributed to: 11th International Symposium on Microwave and Optical Technology (ISMOT'07), Monte Porzio Catone, Italy, Dec 17-21, 2007.Two configurations based on Bragg grating assisted single-ring microresonators are analyzed and simulated. Device characteristics such as bandwidth, sensitivity to loss, effect of external coupling, tunability and group delay are evaluated. The relationship between the resonator mode number and the grating parameters and the rules for selecting appropriate mode numbers are discussed. The dependence of reflection loss on waveguide attenuation and grating reflection coefficient illustrate the analytical results.The support of the Spanish Ministry of Education project CICYT TEC2006-13273-C03-03/MIC and the Natural Sciences and Engineering Research Council of Canada are acknowledged.Publicad
Optomechanical coupling in photonic crystal supported nanomechanical waveguides
We report enhanced optomechanical coupling by embedding a nano-mechanical
beam resonator within an optical race-track resonator. Precise control of the
mechanical resonator is achieved by clamping the beam between two low-loss
photonic crystal waveguide couplers. The low insertion loss and the rigid
mechanical support provided by the couplers yield both high mechanical and
optical Q-factors for improved signal quality
Band splitting and Modal Dispersion induced by Symmetry braking in Coupled-Resonator Slow-Light Waveguide Structures
We study the dispersion relations in slow-light waveguide structures
consisting of coupled microdisk resonators. A group theoretical analysis of the
symmetry properties of the propagating modes reveals an interesting phenomenon:
The degeneracy of the CW and CCW rotating modes is removed, giving rise to two
distinct transmission bands. This effect induces symmetry-based dispersion
which may limit usable bandwidth of such structures. The properties of this
band splitting and its impact on CROW performance for optical communications
are studied in detail
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On-chip supercontinuum generation in nanostructured Ge11.5As24Se64.5 chalcogenide waveguides using Panda-ring resonator
The on-chip scale microring circuit is proposed to numerically investigate the supercontinuum (SC) generation of light power. The device is formed by the chalcogenide Panda-ring resonator with the nanoscale planar waveguide using Ge11.5As24Se64.5chalcogenide glass channel waveguide, air-clad and MgF2glass for lower cladding. The waveguide is designed to exhibit normal dispersion along with a low-energy pumped at 1.55 ÎŒm using a short pulse, which has the duration of 50 fs and peak power ranging from 1 W to 100 W. The numerical result obtained has shown a good-quality SC generation of both the spectral bandwidth and high output peak power. All SC spectral extended to more than 13 ÎŒm by cumulative Kerr nonlinearities. The obtained results can be useful for developing new experimental work in the important area of SC generation on compact chip broadband sources, which can be used in both infrared and radio wave applications
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