Brillouin scattering

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

Observation of pulse delaying and advancement in optical fibers using stimulated Brillouin scattering

Abstract: We demonstrate experimentally that it is possible to control optically the group velocity of an optical pulse as it travels along an optical fiber. To achieve this control we use the effect of Stimulated Brillouin Scattering. In our experiments we have achieved changes in the group index of 10-3 in several kilometer-length fibers, thus leading to pulse delaying and advancement in the range of tens of nanoseconds. We believe that this is the first evidence of such optically-controlled strong delay changes in optical fibers. In this paper we derive the basic theory behind these group-delay changes and we demonstrate the effect in two kinds of fibers which are conventionally used.

Tensile strain dependence of Brillouin frequency shift in silica optical fibers

Abstract: Brillouin frequency shift in a single-mode optical fiber has been measured as a function of tensile strain. The strain coefficient of normalized Brillouin frequency shift C identical to (dv/sub B//d epsilon )/v/sub B/ is found to be 4.4 for silica fibers. This result shows the potential of Brillouin spectroscopy to evaluate tensile strain in the fiber with the strain resolution of about 2*10/sup -4/. The origin of the large strain coefficient is discussed. >

Handbook of nonlinear optics

Abstract: Elements of the theory of nonlinear optics frequency doubling and mixing optical parametric generation, amplification, and oscillation characterization of second order nonlinear optical materials properties of selected second order nonlinearoptical materials nonlinear index of refraction characterization of nonlinear refractive index materials optical properties of selected third order nonlinear optics materials nonlinear absorption experimental techniques in nonlinear absorption ultrafast characterization techniques laser flash photolysis nonlinear absorption properties of selected materials stimulated Raman scattering stimulated Brillouin scattering properties of selected stimulated light-scattering materials theelectro-optic effect.

Recent progress in Brillouin scattering based fiber sensors.

Abstract: Brillouin scattering in optical fiber describes the interaction of an electro-magnetic field (photon) with a characteristic density variation of the fiber. When the electric field amplitude of an optical beam (so-called pump wave), and another wave is introduced at the downshifted Brillouin frequency (namely Stokes wave), the beating between the pump and Stokes waves creates a modified density change via the electrostriction effect, resulting in so-called the stimulated Brillouin scattering. The density variation is associated with a mechanical acoustic wave; and it may be affected by local temperature, strain, and vibration which induce changes in the fiber effective refractive index and sound velocity. Through the measurement of the static or dynamic changes in Brillouin frequency along the fiber one can realize a distributed fiber sensor for local temperature, strain and vibration over tens or hundreds of kilometers. This paper reviews the progress on improving sensing performance parameters like spatial resolution, sensing length limitation and simultaneous temperature and strain measurement. These kinds of sensors can be used in civil structural monitoring of pipelines, bridges, dams, and railroads for disaster prevention. Analogous to the static Bragg grating, one can write a moving Brillouin grating in fibers, with the lifetime of the acoustic wave. The length of the Brillouin grating can be controlled by the writing pulses at any position in fibers. Such gratings can be used to measure changes in birefringence, which is an important parameter in fiber communications. Applications for this kind of sensor can be found in aerospace, material processing and fine structures.