A new Brillouin scattering technique for the investigation of acoustic and opto-acoustic properties: application to polymers

Abstract

Within this paper we propose a versatile Brillouin technique which allows an easy determination of acoustic and opto-acoustic properties of thin films. This new technique is especially suitable for studying acoustic dispersion behaviour at hypersonic frequencies. Typical applications in the field of polymers have been used to demonstrate the efficiency of the proposed scattering technique.

Surface Brillouin scattering on annealed ion-implanted CVD diamond

“…The scattered light was analyzed by a 3+3 pass Sandercock type tandem Fabry Pérot interferometer described in [13]. The Krüger geometry [14] in backscattering mode was used to interpret the SBS data as both direct and indirect scattering mechanisms can be observed when the ion damaged diamond is still relatively transparent and the free polished surface at the opposite side of 95 the implanted layer was held in position against a flat reflective aluminium plate.…”

“…The Peaks labeled L (167 GHz) are bulk longitudinal modes due to direct elastooptic scattering and the peaks labeled A (33 GHz) are due to indirect scattering via the Kruger scattering geometry[14] corresponding to transverse modes of the two samples. Instrumental ghosts are transmission peaks that are a function of the instrument and are useful in calibrating the spectrometer(Color online)where ν is the frequency shift, λ 0 is the wavelength of the incident laser beam 135 and θ i is the angle of incidence that the beam makes with the sample surface's normal.An analysis of the scattering geometry using the Krüger backscattering geometry explained in[16] shows that peak A is a bulk transverse mode probed by indirectly scattered photons as a result of the presence of a back reflective 140 aluminium surface.…”

Local ultrasonic wave velocities in trabeculae measured by micro-Brillouin scattering

“…2. 19 The interaction between incident and scattered light allows for the measurement of phonons that propagate in each direction of the wave vectors q HA and q 180 in one measurement (the frequency is in the GHz range). The wave velocity of q HA is measured in the area where the incident and reflected light interfere.…”

Comparative investigation of elastic properties in a trabecula using micro-Brillouin scattering and scanning acoustic microscopy

“…2. 17 The interaction between incident and scattered light near the mirror enables the measurement of the phonons that propagate in each direction of the wave vectors q HA and q 180 in one measurement (the frequency is gigahertz range). Especially, the wave velocity of q HA is measured in the area where incident and reflected light interfere.…”