11 research outputs found
Piezoelectric Phononic Plates: Retrieving the Frequency Band Structure via All-electric Experiments
We propose an experimental technique based on all-electric measurements to
retrieve the frequency response of a one-dimensional piezoelectric phononic
crystal plate, structured periodically with millimeter-scaled metallic strips
on its two surfaces. The metallic electrodes, used for the excitation of
Lamb-like guided modes in the plate, ensure at the same time control of their
dispersion by means of externally loaded electric circuits that offer
non-destructive tunability in the frequency response of these structures. Our
results, in very good agreement with finite-element numerical predictions,
reveal interesting symmetry aspects that are employed to analyze the frequency
band structure of such crystals. More importantly, Lamb-like guided modes
interact with electric-resonant bands induced by inductance loads on the plate,
whose form and symmetry are discussed and analyzed in depth, showing
unprecedented dispersion characteristics.Comment: This is the version of the article before peer review or editing, as
submitted by an author to Smart Materials and Structures. IOP Publishing Ltd
is not responsible for any errors or omissions in this version of the
manuscript or any version derived from it. The Version of Record is available
online at https://doi.org/10.1088/1361-665X/ab4aa
Dark and Photo-Conductivity Measurement Techniques for Dielectric Materials, Application to LiNbO3
International audienc
Optimization of the output of a solar cell per theoretical and experimental study of the models to one and two exponential
The production of electricity based on the conversion of the sunlight by photovoltaic cells containing crystalline silicon is the way most used on the technological and industrial level Consequently, the development of the terrestrial applications for the energy production requires high-output cells and low cost.The aim of our work is to present a comparative study between both theoretical and experimental models of a solar cell based silicon type PHYWE (connecting four cells in series of 80 mm diameter) to improve photovoltaic performance.This study led to the determination of the parameters of the cell starting from the current-voltage characteristic, the influence of luminous flow on this characteristic as well as the effect of the incidental photons on the solar cell. We justify the interest to use the model with two exponential for the optimization of the output by underlining the insufficiency of the model to one exponential
Influence of the Thermo-Opticity on the Birefringence in an Electro-Optic Modulator: Application to Lithium Tantalate
International audienceThis study presents an examination of the temperature influence of an EO-modulation system on the basis of its thermo-optic (TO) behavior. We have considered the first order contribution of the temperature to the EO modulator response with emphasis on the direct influence of temperature on the birefringence and on the dimensions of the active part existing between both electrodes. The role of the transverse configuration is examined in comparison with its corresponding longitudinal configuration. Finally, we illustrate this work using some significant results obtained with a lithium tantalatemodulator crystal, which is considered as a promising material for EO modulation applications
Optical damage and photoconductivity in iron-doped lithium niobate crystals
International audienc
Optical damage dynamics in reduced nominally pure LiNbO3 crystals
International audienc
Tunable phononic structures using Lamb waves in a piezoceramic plate
International audienc