140 research outputs found
Enhanced coupling to microsphere resonances with optical fibers
Cataloged from PDF version of article.Morphology-dependent resonances (MDR's) of polystyrene microspheres were excited by an optical fiber coupler. For optical elimination of the air-cladding interface at the optical fiber coupler surface, the microsphere was immersed in an index-matching oil. MDR's were observed, even though the relative refractive index between the microsphere and the oil was only 1.09. The observed MDR spectra are in good agreement with the generalized Lorenz-Mie theory and the localization principle. The scattering efficiency into each MDR is estimated as a function of the impact parameter by means of generalized Lorenz-Mie theory. (C) 1997 Optical Society of America
Morphology Dependent Resonances of a microsphere/optical fiber system
Cataloged from PDF version of article.Morphology-dependent resonances of microspheres sitting upon an index-matched single-mode fiber half-coupler are excited by a tunable 753-nm distributed-feedback laser. Resonance peaks in the scattering spectra and associated dips in the transmission spectra for the TE and TM modes are observed. We present a new model that describes this interaction in terms of the fiber-sphere coupling coefficient and the microsphere's intrinsic quality factor Q0. This model enables us to obtain expressions for the finesse and the Q factor of the composite particle-fiber system, the resonance width, and the depth of the dips measured in the transmission spectra. Our model shows that index matching improves the coupling efficiency by more than a factor of 2 compared with that of a non-index-matched system. © 1996 Optical Society of America
Density-potential mappings in quantum dynamics
In a recent letter [Europhys. Lett. 95, 13001 (2011)] the question of whether
the density of a time-dependent quantum system determines its external
potential was reformulated as a fixed point problem. This idea was used to
generalize the existence and uniqueness theorems underlying time-dependent
density functional theory. In this work we extend this proof to allow for more
general norms and provide a numerical implementation of the fixed-point
iteration scheme. We focus on the one-dimensional case as it allows for a more
in-depth analysis using singular Sturm-Liouville theory and at the same time
provides an easy visualization of the numerical applications in space and time.
We give an explicit relation between the boundary conditions on the density and
the convergence properties of the fixed-point procedure via the spectral
properties of the associated Sturm-Liouville operator. We show precisely under
which conditions discrete and continuous spectra arise and give explicit
examples. These conditions are then used to show that in the most physically
relevant cases the fixed point procedure converges. This is further
demonstrated with an example.Comment: 20 pages, 8 figures, 3 table
Influence of boundary slip on the optimal excitations in thermocapillary driven spreading
A note on multiple flow equilibria
A set of ordinary differential equations describing a mechanical system subject to forcing and dissipation is considered. A topological argument is employed to show that if all time-dependent solutions of the governing equations are bounded, the equations admit N steady solutions, where N is a positive odd integer and where at least ( N −1)/2 of the steady solutions are unstable. The results are discussed in the context of atmospheric flows, and it is shown that truncated forms of the quasigeostrophic equations of dynamic meteorology and of Budyko-Sellers climate models satisfy the hypotheses of the theorem.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43139/1/24_2004_Article_BF00881609.pd
Solução concentrada de albumina eqüina na fluidoterapia em eqüinos com desidratação leve a moderada
Cognitive Science of Religion and the Study of Theological Concepts
Abstract The cultural transmission of theological con-cepts remains an underexplored topic in the cognitive sci-ence of religion (CSR). In this paper, I examine whether approaches from CSR, especially the study of content biases in the transmission of beliefs, can help explain the cultural success of some theological concepts. This approach reveals that there is more continuity between theological beliefs and ordinary religious beliefs than CSR authors have hitherto recognized: the cultural transmission of theological concepts is influenced by content biases that also underlie the reception of ordinary religious concepts
Electronic specific heat of sodium tungsten bronze
The design and operation of a calorimeter for use in the temperature range 1.8-4.2°K. are presented, and the methods used in the treatment of data and calculation of results are discussed.</p
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