Concept

Loi de Bragg

Publications associées (115)

Surface emitting Terahertz Photonic Crystal Quantum Cascade Laser realized by Bragg boundary condition

Romuald Houdré, Jérôme Faist, Zhaolu Diao, Christopher Bonzon

We theoretically and experimentally investigate a band edge Photonic Crystal (PhC) Quantum Cascade Laser (QCL) operating at 3.1 THz. The surface emission is achieved by using a second-order Bragg grating at the PhC tile boundaries. Highly directional surfa ...

Ieee2012

Integrated hybrid Raman/fiber Bragg grating interrogation scheme for distributed temperature and point dynamic strain measurements

Marcelo Alfonso Soto Hernandez

We propose and experimentally demonstrate the feasibility of an integrated hybrid optical fiber sensing interrogation technique that efficiently combines distributed Raman-based temperature sensing with fiber Bragg grating (FBG)-based dynamic strain measur ...

2012

Combining neutron diffraction and imaging for residual strain measurements in a single crystal turbine blade

Helena Van Swygenhoven

Neutron diffraction is a technique often used for the non-destructive characterization of residual stresses in engineering materials and components. Measuring stresses within partially hollow objects with complex internal geometry however is challenging du ...

2012

Stress changes in H2-loaded SMF optical fibers induced by cw-Ar+ 244 nm irradiation

Hans Georg Limberger, Georgios Violakis, Nandita Aggarwal

Bragg gratings were inscribed in H2-loaded SMF-28e optical fibers and measured for axial stress changes for various exposure doses. Mean refractive index changes as high as 7.5 × 10-3 were observed under cw-244 nm irradiation of 143 W/cm2. Bragg grating re ...

Optical Soc Amer2012

Low energy impact damage monitoring of composites using dynamic strain signals from FBG sensors - Part I: Impact detection and localization

John Botsis, Joël Cugnoni, Jeannot Frieden

Fiber reinforced composite materials risk to suffer from subsurface, barely visible, damage induced by transverse relatively low energy impacts. This two-paper series presents a method for the localization of an impact and identification of an eventual dam ...

2012

Deaging and Asymmetric Energy Landscapes in Electrically Biased Ferroelectrics

Dragan Damjanovic, Jun Chen

In ferroic materials, the dielectric, piezoelectric, magnetic, and elastic coefficients are significantly affected by the motion of domain walls. This motion can be described as the propagation of a wall across various types and strengths of pinning center ...

American Physical Society2012

High-resolution hard-x-ray microscopy using second-order zone-plate diffraction

Giorgio Margaritondo

Odd-order diffraction of zone plates (ZPs) is already used for x-ray microscopy but the potential offered by even-order diffraction must still be fully exploited. Width differences between lines and interline spaces transfer intensity from odd-order to eve ...

2011

Observation of multiple volume reflection by different planes in one bent silicon crystal for high-energy negative particles

Multiple volume reflection by different planes passing through the 〈111〉 axis in a bent silicon crystal was observed for the first time for 150 GeV/c negative particles, π- mesons, at one of the secondary beams of the CERN SPS. The beam of π- mesons was de ...

2011

Texture vs morphology in ZnO nano-rods: On the x-ray diffraction characterization of electrochemically grown samples

Texture characterization in thin films from standard powder x-ray diffraction (XRD) rely on the comparison between observed peak relative intensities with those of powder diffraction standards of the same compound, trough the so-called texture coefficient ...

American Institute of Physics2011

Synchrotron X-ray diffraction study on a single nanowire of PX-phase lead titanate

Nava Setter, Silviu Cosmin Sandu, Jin Wang

Synchrotron X-ray diffraction (XRD) measurements of Pb-Ti-O fine acicular crystals (nanowires) of the so-called PX-phase have been performed. The theta-2 theta patterns of the nanowires dispersed on substrates with two different geometries indicated that t ...

2010

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