Search results for "Guide"

Causal drugs and therapeutic measures for medication-associated osteonecrosis of the jaws-Data from German practice guideline.

2020

Photo-acoustic phase-delayed excitation of guided waves in coated bone phantoms

2013

Photo-acoustic skeletal quantitative ultrasound enables assessment of the fundamental flexural guided wave (FFGW) propagating in bone. This mode, consistent with the F(1,1) tube mode can now be measured through a coating of soft tissue. Interference due to ultrasound propagation in the soft tissue surrounding the bone is reduced by using phase-delayed ultrasound excitation. Photo-acoustic phase-delayed excitation was done on five axisymmetric bone phantoms (1-5 mm wall thickness), coated by a 5 mm thick soft-tissue mimicking layer. A fiber head comprising a linear array of four optical fibers (400 μm diameter), illuminated by pulsed laser diodes (905 nm wavelength) generated ultrasound. Thi…

Polymer Halide Perovskites-Waveguides Integrated in Nanocellulose as a Wearable Amplifier-Photodetector System

2018

Semiconductor organometallic halide (CH 3 NH 3 PbX 3 , X=Cl, Br, I) perovskites (MHP) have emerged as a very high promising material for optoelectronics. Their large absorption coefficients, high electronic mobilities, excellent quantum yield of emission at room temperature and tunable band-gap with the composition resulted in a new generation of photovoltaics and electronic devices. In this work, HPVK materials are successfully incorporated on a nanocellulose (NC) substrate with the intention to exploit the interesting properties of HPVK materials to construct wearable devices. In particular, a bilayer Poly(methyl methacrylate) /HPVK deposited on NC resulted in a suitable waveguide to demo…

Ultrasonic Guided Wave Inspection of Bonded Lap Joints: Noncontact Method and Photoelastic Visualization

2001

The main topic of this paper is the nondestructive inspection of adhesively bonded lap joints by using ultrasonic guided (plate) waves. A noncontact, couplant-free method that employs capacitive air-coupled transducers is demonstrated for the inspection of thin aluminum joints with dimensions typical of aircraft fuselage and wing panels. Two types of bond defects, disbonded regions and regions of poorly cured (low-cohesive-strength) adhesive, are successfully detected by measuring the amplitude decrease of selected plate waves leaking from one adherend to the other one through the bondline. It is shown that proper choice of the vibrating mode structure, in terms of cross-sectional displacem…

Multi-line NIR-RGB emission in Nd:LiNbO3 RPE optical waveguides

2007

Simultaneous generation of four spectral emission lines has been achieved in Nd-doped lithium niobate reverse proton exchange optical waveguide cavities. Using a pump at 800 nm, the four lines were found and they are due to lasing at 1.3735 combined with parametric conversion at 0.687, 0.574 and 0.4 mum.

Efficient excitation of photoluminescence in a two-dimensional waveguide consisting of a quantum dot-polymer sandwich-type structure

2014

International audience; In this Letter, we study a new kind of organic polymer waveguide numerically and experimentally by combining an ultrathin (10–50 nm) layer of compactly packed CdSe/ZnS core/shell colloidal quantum dots (QDs) sandwiched between two cladding poly(methyl methacrylate) (PMMA) layers. When a pumping laser beam is coupled into the waveguide edge, light is mostly confined around the QD layer, improving the efficiency of excitation. Moreover, the absence of losses in the claddings allows the propagation of the pumping laser beam along the entire waveguide length; hence, a high-intensity photoluminescence (PL) is produced. Furthermore, a novel fabrication technology is develo…

A precise photometric ratio via laser excitation of the sodium layer - I. One-photon excitation using 342.78 nm light

2020

The largest uncertainty on measurements of dark energy using type Ia supernovae is presently due to systematics from photometry; specifically to the relative uncertainty on photometry as a function of wavelength in the optical spectrum. We show that a precise constraint on relative photometry between the visible and near-infrared can be achieved in upcoming surveys (such as in LSST at the Vera C. Rubin Observatory) via a mountaintop-located laser source tuned to the 342.78 nm vacuum excitation wavelength of neutral sodium atoms. Using a high-power (500 W) laser modified from laser guide star studies, this excitation will produce an artificial star (which we term a "laser photometric ratio s…

Color Tuning and White Light by Dispersing CdSe, CdTe, and CdS in PMMA Nanocomposite Waveguides

2013

In this paper, active nanocomposite waveguides based on the dispersion of CdS, CdTe, and CdSe colloidal quantum dots (QDs) in PMMA are proposed. Their propagation properties are studied as a function of the concentration of nanoparticles in the polymer using the variable length stripe method. When the three nanostructures are dispersed in the same film, the structure is able to waveguide the three basic colors: red (CdSe), green (CdTe), and blue (CdS), it being possible to engineer any waveguided color by an appropriate choice of the filling factor of each QD in the PMMA matrix. For this purpose, it is important to take into account reabsorption effects and the Förster energy transfe…

Real-time and low-cost sensing technique based on photonic bandgap structures

2011

[EN] A technique for the development of low-cost and high-sensitivity photonic biosensing devices is proposed and experimentally demonstrated. In this technique, a photonic bandgap structure is used as transducer, but its readout is performed by simply using a broadband source, an optical filter, and a power meter, without the need of obtaining the transmission spectrum of the structure; thus, a really low-cost system and real-time results are achieved. Experimental results show that it is possible to detect very low refractive index variations, achieving a detection limit below 2 x 10(-6) refractive index units using this low-cost measuring technique. (C) 2011 Optical Society of America[

Efficient surface plasmon field confinement in one-dimensional crystal line-defect waveguides

2006

International audience; The authors operate a near-field optical microscope to investigate surface plasmon polariton (SPP) propagation along linear waveguides opened into one-dimensional (1D) plasmonic crystals, i.e., crystals featuring a single lattice plane orientation. They show that efficient SPP field confinement can be achieved by this type of waveguide although no band gap exists in the direction perpendicular to the waveguide axis. From computed wave-vector diagrams, they show that 1D plasmonic crystals can open a wide range of prohibited propagation directions preventing from a significant coupling of the waveguide SPP modes with the crystal Bloch modes. Finally, the authors demons…