Diffusion de la lumière et des rayons X par un corps transparent homogène

Numerical modelling on stimulated Brillouin scattering characterization for Graphene-clad tapered silica fiber

“…The incident wave which is also known as the pump wave has to be higher than threshold power to generate acoustic wave [1]. The process of sound vibration fluctuates the refractive index of optical wave and scatters the injected pump wave.…”

Simulation of simultaneous photonic and phononic band gaps in Sapphire

“…The studies of periodic structures of pillars which ala e-mail: bentarki.houda@gmail.com low the existence of forbidden bands were conducted, various structures containing only air inclusions [14][15]. The acousto-optical interaction started since the 60's, thanks to the invention of the laser and Leon Brillouin in 1914, which made the first theory of the coupling of a light wave with a hyper-sonic wave [16]. Leon Brillouin theory, published in 1921, provides that a liquid traversed by a hypersonic wave causes periodic variations of constraints that create, by photo-elastic effect, changes in the refractive index, then behaving as a network of diffraction for light.…”

“…Leon Brillouin theory, published in 1921, provides that a liquid traversed by a hypersonic wave causes periodic variations of constraints that create, by photo-elastic effect, changes in the refractive index, then behaving as a network of diffraction for light. [16] This has resulted in the following years, a series of studies both theoretical and experimental involving photonphonon interaction. Other studies, this time based on other than a 2D square lattice structures, [17][18] have emerged.…”

High Frequency Acoustics in Colloid-Based Meso- and Nanostructures by Spontaneous Brillouin Light Scattering

“…In fact, when measuring the sound propagating in a material, it is not absolutely necessary to generate the hypersound artificially, since hypersonic phonons are thermally excited at temperatures far away from 0 K. [24] These phonons can be probed by inelastic light scattering, i.e., spontaneous Brillouin light scattering (BLS) in the GHz-range (related to the mesoscopic length scale) and Raman scattering in the THz-range (for the nanoscopic length scale). [25,26] Another possibility is pump-probe spectroscopy, where a strong laser pulse impinges on a sample and a second probe laser is used to measure the reflectivity of the sample as a function of time. [27,28] After Fourier transformation that approach also delivers information about the frequencies of sound in the probed material, however, after an induced perturbation and not spontaneously.…”