Brillouin scattering

About: Brillouin scattering is a research topic. Over the lifetime, 11426 publications have been published within this topic receiving 178306 citations.

Surface Brillouin scattering from acoustic phonons. II. Application to semiconductors

Abstract: The theory of Brillouin scattering from corrugated surfaces developed previously has been applied to semiconductors. The available spectra measured with 5145 AA light has been used for evaluating the elasto-optic constants (k11, k12, k44) of the medium. For GaAs k11=42.5, k12=51 and k44=25.5. This is the first determination of these constants in GaAs at this wavelength, where other techniques are not applicable. For silicon k11=53, k12=25 and k44=23. It is also shown that in opaque semiconductors the elasto-optic coupling depends strongly on the surface orientation.

Splitting of spin excitations in nanometric rings induced by a magnetic field

Abstract: We present a Brillouin light scattering investigation of the eigenmode spectrum of nanometric permalloy rings as a function of the applied magnetic field. In particular, different splitting effects induced by the applied magnetic field on the radial and azimuthal excitations have been observed and explained in terms of either mode localization or symmetry. The dynamical matrix approach has been used to calculate the whole set of eigenvectors and eigenvalues of the system, in both the vortex and saturated states.

Temperature dependence of parametric instabilities in the context of the shock-ignition approach to inertial confinement fusion

Abstract: The role of the coronal electron plasma temperature for shock-ignition conditions is analysed with respect to the dominant parametric processes: stimulated Brillouin scattering, stimulated Raman scattering, two-plasmon decay (TPD), Langmuir decay instability (LDI) and cavitation TPD instability and cavitation are sensitive to the electron temperature At the same time the reflectivity and high-energy electron production are strongly affected For low plasma temperatures the LDI plays a dominant role in the TPD saturation An understanding of laser–plasma interaction in the context of shock ignition is an important issue due to the localization of energy deposition by collective effects and hot electron production This in turn can have consequences for the compression phase and the resulting gain factor of the implosion phase

Forward Brillouin scattering acoustic impedance sensor using thin polyimide-coated fiber

Abstract: The standard single-mode fiber has been demonstrated as an optomechanical sensor recently to measure the acoustic impedances of surrounding liquids by means of the generation and detection of forward-stimulated Brillouin scattering (FSBS). FSBS allows the mechanical properties of an external material to be probed directly through the interaction of guided light and transverse sound waves that occurs entirely inside the fiber structure. In this technique, having a low-loss interface between the fiber bulk and the external medium is essential for precise measurement; however, it leads to the necessary but impractical removal of the thick polymer fiber coating in most reported methods. Here, we use a commercially available 80-μm-diameter optical fiber coated with a 8-μm-thick polyimide coating layer to measure the acoustic impedances of the surrounding liquids, showing accurate measurement results while retaining the mechanical strength of the fiber.

Temperature-compensated distributed hydrostatic pressure sensor with a thin-diameter polarization-maintaining photonic crystal fiber based on Brillouin dynamic gratings.

Abstract: A temperature-compensated distributed hydrostatic pressure sensor based on Brillouin dynamic gratings (BDGs) is proposed and demonstrated experimentally for the first time, to the best of our knowledge. The principle is to measure the hydrostatic pressure induced birefringence changes through exciting and probing the BDGs in a thin-diameter pure silica polarization-maintaining photonic crystal fiber. The temperature cross-talk to the hydrostatic pressure sensing can be compensated through measuring the temperature-induced Brillouin frequency shift (BFS) changes using Brillouin optical time-domain analysis. A distributed measurement of hydrostatic pressure is demonstrated experimentally using a 4-m sensing fiber, which has a high sensitivity, with a maximum measurement error less than 0.03 MPa at a 20-cm spatial resolution.