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Showing 1 to 20 of 69 for “"Brillouin scattering"”.
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Brillouin scattering investigation of nanomagnetic structures
Brillouin light scattering is employed to study the dynamical properties of arrays of vertical ferromagnetic nanowires and nanorings, which show great promise as high-density magnetic storage and sensor devices. Three closely related projects are reported: (1) observation of bulk magnon …
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Brillouin scattering and coherent phonon generation.
Massachusetts Institute of Technology. Dept. of Physics. Thesis. 1965. Ph.D.
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On the Rayleigh -Brillouin scattering in air
… system that can directly measure the Rayleigh-Brillouin scattering (RBS) spectra, from which the wind, temperature, and turbulence in the troposphere can be measured. Its transmitter is a double-frequency Nd-YAG laser at 532nm. Most of the data used in this research were taken on 31 July …
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Brillouin scattering in cubic crystals using lasers.
Massachusetts Institute of Technology. Dept. of Physics. Thesis. 1965. M.S.
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Stimulated Brillouin scattering in an on-chip microdisk resonator
Brillouin scattering is the scattering of light from sound waves in a medium. There are three waves involved in the process: two optical waves (pump and scattered light) and one acoustic wave, and the scattering process is restricted through the conservation of momentum and energy. Stimulated …
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Brillouin scattering from opaque semiconducting alloys and thin films
Brillouin scattering spectra were measured in MBE grown single crystal films of A1xGal_xAs alloys and AlxGal_xAs -GaAs supedattices on GaAs substrates, and GaAs films grown on miscut Si substrates. To detect the Brillouin shifted light against the strong elastic background present in opaque …
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Brillouin scattering from single-crystal dysprosium and gadolinium films
Brillouin light scattering studies have been made on the temperature dependence and dispersion of long-wavelength acoustic phonons in single-crystal Dy films and long-wavelength acoustic magnons in single-crystal Gd films. The spectra were analyzed by using elastic and magnetic continuum models for …
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Brillouin scattering from single-crystal dysprosium and gadolinium films
"Brillouin light scattering studies have been made on the temperature dependence and dispersion of long-wavelength acoustic phonons in single-crystal Dy films and longwavelength acoustic magnons in single-crystal Gd filins. The spectra were analyzed by using elastic and magnetic continuum models …
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Spontaneous brillouin scattering quench diagnostics for large superconducting magnets
… the temperature and strain based on spontaneous Brillouin scattering in an optical fiber. Using an extremely narrow (200 Hz) linewidth Brillouin laser with very low noise as a frequency shifted local oscillator, the frequency shift of spontaneous Brillouin scattered light was measured using …
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STIMULATED BRILLOUIN SCATTERING SUPPRESSION VIA TEMPERATURE GRADIENTS IN FIBER AMPLIFIERS
… is explored. The limiting factor, Stimulated Brillouin Scattering (SBS), is suppressed with a single-step temperature gradient. A similar fiber amplifier to the 177W amplifier is constructed and tested at various temperatures from 90C to -120C. The Brillouin frequency is observed to shift with …
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A study of stimulated Brillouin scattering in laser produced plasmas
… instabilities, in particular stimulated Brillouin scattering (SBS), for the creation of such pulses is found to have great potential. Analysis from numerical, analytical and experimental studies are presented within this thesis which were constructed to develop a platform of knowledge to …
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Studies of simulated Brillouin scattering in optical fibers and applications
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.
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Distributed Pressure and Temperature Sensing Based on Stimulated Brillouin Scattering
Brillouin scattering has been verified to be an effective mechanism in temperature and strain sensing. This kind of sensors can be applied to civil structural monitoring of pipelines, railroads, and other industries for disaster prevention. This thesis first presents a novel fiber sensing scheme …
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Simulation of optical fibre communication systems influenced by stimulated brillouin scattering
… also been innovatively improved by allowing the Brillouin Shift Frequency (BS) to vary over the model fibre length, for the nonuniform fibre model (NFM) mode, or to remain constant, for the uniform fibre model (UFM) mode. The assumption of a Gaussian probability density function (pdf) for the BSF …
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Brillouin scattering induced transparency and generation of slow and fast light
… creates an interference pathway. In this study, Brillouin scattering analogue of EIT is demonstrated using the two optical modes that are coupled through a phase matched acoustic mode. The coherent coupling of two energy levels is emulated by the acousto-optic interaction of Brillouin scattering. …
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Time and temperature dependence of stimulated brillouin scattering in fused silica
Several aspects of stimulated Brillouin scattering which relate to the determination of acoustic phonon lifetime (Tp) have been investigated. Fused silica was selected as the principal material to be studied because of its optical and acoustic isotropy and its availability in large, optical quality …
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Stimulated Brillouin scattering effects and suppression techniques in high power fiber amplifiers
… a model for numerical analysis of stimulated Brillouin scattering (SBS) effects and the development of suppression techniques for the realization of increased output power levels for high power ytterbium-doped dual clad fiber amplifiers. The overall objective of this effort is to develop and …
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Error analysis for distributed fibre optic sensing technology based on Brillouin scattering
… the work conducted on error analysis for Brillouin Optical Time Domain Reflectometry (BOTDR), a distributed strain sensing technology used for monitoring the structural performance of infrastructures. Although BOTDR has been recently applied to many infrastructure monitoring applications, …
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Distributed optical fibre sensors based on the coherent detection of spontaneous Brillouin scattering
… based on the coherent detection of spontaneous Brillouin scattering. To further improve the sensing range and the sensor's performance, the use of Raman amplification was investigated utilising different Raman pump configurations. Using frequency measurements only, a temperature resolution of 5 …
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The elastic properties of fine-grained polycrystalline and amorphous samples by Brillouin scattering
… polycrystalline and amorphous materials using Brillouin scattering. Our initial experiments were performed on silica minerals, among the most abundant minerals in the crust, and MgO, one of the major components of Earth’s lower mantle. Four silica minerals (wood opal, hyalite, opal-CT and …
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