Olivier Durand

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We present a new optoelectronic architecture, based on parallel canceled delay lines, that performs programmable filtering of microwave signals. The new architecture can process optically carried microwave signals over frequency bandwidths as large as 20 GHz, with a time-frequency product up to 10(3). The operating principle of this structure is detailed,(More)
The durability of concrete structures is a major issue in civil engineering. Cover concrete monitoring is particularly important as it is in direct contact with the outside. High frequency surface waves (50-200 kHz) are adapted to provide information about this part of concrete, since they investigate materials at a depth close to the wavelength. The high(More)
The French national research project SENSO aims at providing a methodology combining several non destructive testing methods to evaluate indicators required for assessing the durability of concrete cover. A large set of 0.5m x 0.25m x 0.12m slabs has been built for various water/cement ratios, aggregate sizes and type. Those slabs have been subsequently(More)
In order to use nondestructive techniques (NDT) for the survey of reinforced concrete structures, it is important to show that they are able to measure the cover concrete characteristics related to its durability. For this purpose, various NDT were implemented to evaluate the mechanical and physical properties of concretes whose porosity is ranging from(More)
A new global optimization algorithm is presented and applied to the design of high-channel-count multichannel filters based on sampled Fiber Bragg Gratings. We focus on the realization of particular designs corresponding to multichannel filters that consist of 16 and 38 totally reflective identical channels spaced 100 GHz. The results are compared with(More)
The physical origin of the nonlinear scattering of light induced by focusing of intense laser pulses onto carbon black suspensions (CBS's) is discussed through the interpretation of limitation, time-resolved pump-probe transmission, and angularly and time-resolved scattering experiments performed with picosecond resolution. Comparison of the experimental(More)
Low frequency dynamics has been studied in a CH3NH3PbBr3 hybrid perovskite single crystal by using four different spectroscopy techniques: coherent inelastic neutron, Raman and Brillouin scatterings, and ultrasound measurements. Sound velocities were measured over five decades in energy to yield the complete set of elastic constants in a hybrid halide(More)
This article will form part of a virtual special issue of the journal, presenting some highlights of the 12th Biennial Conference on High-Resolution X-ray Diffraction and Imaging (XTOP2014). This study is carried out in the context of III–V semiconductor monolithic integration on silicon for optoelectronic device applications. X-ray diffraction is combined(More)
We propose a novel phase-matching scheme in GaP whispering-gallery-mode microdisks grown on Si substrate combining modal and 4¯ -quasi-phase-matching for second-harmonic-generation. The technique consists in unlocking parity-forbidden processes by tailoring the antiphase domain distribution in the GaP layer. Our proposal can be used to overcome the(More)