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Brillouin scattering
About: Brillouin scattering is a research topic. Over the lifetime, 11426 publications have been published within this topic receiving 178306 citations.
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TL;DR: In this article, the refractive index of BP was measured in the visible spectral range by means of the Brewster angle method, and the elastic constants were determined by Brillouin scattering.
120 citations
TL;DR: The elastic constants of SbSI in the neighbourhood of the ferroelectric transition have been determined from high resolution backscattering measurements using a double-passed, fully stabilised, scanning Fabry-Perot interferometer as mentioned in this paper.
120 citations
TL;DR: In this article, the authors demonstrate an optical time-domain distributed fiber sensor showing the highest spatial resolution ever reported based on Brillouin dynamic grating in a polarization-maintaining fiber.
Abstract: We demonstrate an optical time-domain distributed fiber sensor showing the highest spatial resolution ever reported based on Brillouin dynamic grating in a polarization-maintaining fiber. In our scheme, the acoustic gratings containing the information on the local Brillouin frequency are generated by a long pump pulse in one polarization, and read out by a short probe pulse in the orthogonal polarization at a clearly distinct optical frequency from the pump. In the experiment, distributed temperature measurements over a 20 m fiber are performed with 1.2 cm spatial resolution.
120 citations
Patent•
13 Apr 1989TL;DR: In this article, the authors proposed a soliton fiber communications system with pump radiation injected at one or more intermediate fiber locations, where the average intensity of pump radiation in a first spectral interval, centered on any wavelength λp in the pump radiation spectrum and of width equal to the Brillouin line width of the fiber at λ p, is to be less than that average intensity in the first spectrum interval that results in conversion of 10% of the radiation in the 1-minimization interval to stimulated Brilloustime radiation.
Abstract: An optical fiber communications system with Raman amplification of the signal radiation comprises a broadband pump radiation source (15), or, preferably, a multiplicity of pump radiation sources and polarization maintaining optical fiber (10) as the transmission medium. The sources are selected to result in a pump radiation spectrum such that pump radiation intensity in the fiber core is less than a critical intensity Ic. In particular, the average intensity of pump radiation in a first spectral interval, centered on any wavelength λp in the pump radiation spectrum and of width equal to the Brillouin line width of the fiber at λp, is to be less than that average intensity in the first spectral interval that results in conversion of 10% of the radiation in the first spectral interval to stimulated Brillouin radiation. Use of a multiplicity of pump sources not only can reduce pump noise and pump depletion due to stimulated Brillouin scattering, but typically also can result in enhanced system reliability and lower cost. In a preferred embodiment, the invention is a soliton fiber communications system, with pump radiation injected at one or more intermediate fiber locations.
119 citations
TL;DR: In this article, the effects of chain confinement and the free surface on the mechanical properties of thin polystyrene (PS) films were investigated by measuring the velocity of film-guided acoustic phonons in films with thickness varying from less than to greater than the average end-to-end distance of the unperturbed molecules.
Abstract: We have used Brillouin light scattering (BLS) to measure the room-temperature, high-frequency mechanical properties of thin freely standing polystyrene (PS) films. We have investigated the effects of chain confinement and the free surface on the mechanical properties by measuring the velocity of film-guided acoustic phonons in films with thicknesses ranging from less than to greater than the average end-to-end distance of the unperturbed molecules ${R}_{\mathrm{EE}}.$ We find that the measured, room-temperature sound velocities are the same, to within $\ifmmode\pm\else\textpm\fi{}1%,$ for all films that have glass transition temperatures that differ by as much as 65 K. Our results, which differ markedly from those of recent picosecond acoustic measurements, are discussed in terms of models proposed to explain anomalous glass transition behavior in thin polymer films. A careful analysis of the BLS data reveals that, at room temperature, the mechanical stiffness, mass density, and thermal expansion of thin, freely standing PS films in the glassy state are consistent with bulk values for all film thicknesses.
119 citations