2,382,951 research outputs found
Full three-dimensional wavelength-scale plasmomechanical resonator
No full textPlasmomechanical systems have received considerable interest in mediating the strong interaction between the optical field and mechanical motion. However, typical plasmomechanical systems based on mechanical oscillators that are significantly larger than the wavelength of light do not take full advantage of the optical field concentration beyond the optical diffraction limit of the employed plasmonic resonators. Here we present a full three-dimensional wavelength-scale plasmomechanical resonator consisting of a plasmonic nano-antenna and a hydrogen silsesquioxane nano-wall. The experimental results demonstrated the precise detection of longitudinal mechanical oscillation on a picometer scale, and we investigated the tunability and thermoelastic effect of the mechanical resonance. (C) 2021 Optical Society of America
파장 정도 크기를 가진 광결정 레이저에 관한 연구
No full text학위논문(박사) - 한국과학기술원 : 물리학과, 2009.2, [ v, 135 p. ]The smallest possible laser has long been a challenging and exciting issue in the laser and quantum optics communities. Owing to advances in semiconductor crystal growth and fabrication techniques, lasing actions in various micrometer-size cavities in solids have been successfully performed. The size of semiconductor micro-lasers has become truly wavelength-scale as witnessed by the demonstration of photonic crystal nano-cavities. Particularly, high-quality photonic crystal cavities down to the wavelength scale offer the distinct possibility of a thresholdless laser and a single photon source. Strong coupling phenomena have also been experimentally observed in photonic crystal cavities containing semiconductor quantum dots. However, a number of issues, such as a fully three-dimensional analysis of light-matter interaction in photonic crystal cavities, an electrically driven lasing operation for a practical device, and spectral and spatial tuning of the resonant modes of the photonic crystal, remain to be addressed before it is possible to practically realize these high-performance optical applications. In this thesis, solutions for the issues are proposed and demonstrated, representing small but meaningful steps toward the ultimate creation of quantum optical devices using wavelength-scale photonic crystal cavities.
First, a three-dimensional finite-difference time-domain method that can handle dispersive and dynamic nonlinear-gain media such as semiconductor quantum wells and quantum dots is proposed and realized. The effect of carrier diffusion is included through the formulation of laser rate equations. Through this three-dimensional nonlinear gain FDTD method, rich laser-dynamics behaviors, such as the lasing threshold, the relaxation oscillations, and the spatial hole burning, are directly observed from a hexapole mode. Also examined and measured are interesting characteristics of Rabi splitting between a wavelength-scale PhC cavity mode and a single qua...한국과학기술원 : 물리학과
Controlled sub-nanometer tuning of photonic crystal resonator by carbonaceous nano-dots
No full textWe propose and demonstrate a scheme that enables spectral tuning of a photonic crystal high-quality resonant mode, in steps finer than 0.2 nm, via electron beam induced deposition of carbonaceous nano-dots. The position and size of a nano-dot with a diameter of < 100 nm are controlled to an accuracy on the order of nanometers. The possibility of selective modal tuning is also demonstrated by placing nano-dots at locations pre-determined by theoretical computation. The lasing threshold of a photonic crystal mode tends to increase when a nano-dot is grown at the point of strong electric field, showing the absorptive nature of the nano-dot. (c) 2008 Optical Society of America.One of authors, Min-Kyo Seo, would like to thank Ridah Sabouni, Dr. Kevin Hennessy, and
Prof. Evelyn Hu at University of California at Santa Barbara for helpful discussions. This
work was supported by the Korea Science and Engineering Foundation (KOSEF) (No.ROA-
2006-000-10236-0) and the Korea Foundation for International Cooperation of Science and
Technology (KICOS) (No. M60605000007-06A0500-00710) through grants provided by the
Korean Ministry of Science and Technology (MOST). H. G. P. acknowledges support by the
Seoul R&BD Program
Reconfigurable microfiber-coupled photonic crystal resonator
No full textWe propose and demonstrate reconfigurable microfiber-coupled photonic crystal (PhC) lasers. In this generic configuration, the position of a PhC resonator can be defined (and redefined) repeatedly by simply relocating a curved microfiber along the linear PhC waveguide. In the proximity of the PhC waveguide in contact with the microfiber, the cutoff frequency (effective index) of the PhC waveguide becomes smaller (larger) than that of a bare PhC waveguide. Accordingly, when a curved microfiber is in contact with the PhC waveguide, a linear PhC resonator having Gaussian-shaped potential well is formed. Experimentally we confirm the formation of the reconfigurable resonator by observing laser operation slightly below three available band edges. (C) 2007 Optical Society of America
Plasmon-suppressed vertically-standing nanometal structures
No full textThe authors report plasmon-suppressed vertically-standing nanometal-stripe-array structures fabricated by Ar ion sputtering after electron-beam lithography and Ag deposition. When the width of the Ag stripe is comparable to the skin depth of a metal (similar to 20 nm), the particle plasmon resonance is strongly suppressed for electric fields oscillating perpendicular to the length of the stripe. This suppression of the particle plasmon excitation is attributed to the limited movement of free electrons localized near the bottom of Ag stripe. This plasmon-suppressed vertically-standing nanometal structures could be used for broad band polarizers. (C) 2008 Optical Society of America
Vibration and damping characteristics of composite laminates using shear deformable finite element
No full textDr. Kyo Koike, and car in front of Columbus Sanitarium in Seattle
No full textPH Coll 262.H-39To order a reproduction, inquire about permissions, or for information about prices see: http://www.lib.washington.edu/specialcollections/services/reproduction/reproduction Please cite the Order NumberScanned from a photographic print at 100 dpi in JPEG format at compression rate 3 and resized to 768x600 ppi. 201
Energy Crop Supply in France: A Min-Max Regret Approach
No full textThis paper attempts to estimate energy crop supply using an LP model comprising hundreds of representative farms of the arable cropping sector in France. In order to enhance the predictive ability of such a model and to provide an analytical tool useful to policy makers, interval linear programming (ILP) is used to formalise bounded rationality conditions. In the presence of uncertainty related to yields and prices it is assumed that the farmer minimises the distance from optimality once uncertainty resolves introducing an alternative criterion to the classic profit maximisation rationale. Model validation based on observed activity levels suggests that about 40% of the farms adopt the min-max regret criterion. Then energy crop supply curves, generated by the min-max regret model, are proved to be upward sloped alike classic LP supply curves.interval linear programming, min-max regret, energy crops, France, Crop Production/Industries, Resource /Energy Economics and Policy, C61, D81, Q18,
Reconfigurable Periodic Liquid Crystal Defect Array via Modulation of Electric Field
No full textTopological defects in liquid crystal (LC) phases have been considered critical from the areas in topology and self-assembly, as well as in applications such as optical vortex generation, particle manipulation system, and template for material micropatterning. An approach for generating and modulating various patterns of LC defects is presented in a single cell by varying the electrode configurations. Periodic LC defect arrays including -1 topological defect in the nematic phase can be achieved by simply adjusting crossed electrodes. Specifically, the fourfold symmetric -1 defect pattern is used as a vortex beam generator and a particle trapping agent with control either of the frequency of the applied electric field or the temperature. The approach suggested here would be beneficial to extend the use of LC patterns in lithographic tools and optoelectronic devices.
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