scispace - formally typeset
Search or ask a question
Topic

Brillouin zone

About: Brillouin zone is a research topic. Over the lifetime, 13849 publications have been published within this topic receiving 383077 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: A kind of high-repetition-rate distributed Brillouin sensor is proposed and experimentally demonstrated based on optical correlation-domain analysis with differential frequency modulation, where the optical frequencies of the pump and the probe waves are modulated at slightly different RFs so that the temporal position of the measurement is continuously and repeatedly swept along a fiber under test.
Abstract: A kind of high-repetition-rate distributed Brillouin sensor is proposed and experimentally demonstrated based on optical correlation-domain analysis with differential frequency modulation, where the optical frequencies of the pump and the probe waves are modulated at slightly different RFs so that the temporal position of the measurement is continuously and repeatedly swept along a fiber under test. A distribution map of Brillouin frequency variation along a 100 m optical fiber is acquired at a repetition rate of 20 Hz with an accuracy of ±2.5 MHz and a spatial resolution of about 80 cm.

81 citations

Journal ArticleDOI
TL;DR: In this article, a theoretical description of stimulated Brillouin backscatter when the fluctuation source may be neglected and the scatter grows exclusively from the nonabsorbed light is given. And theoretical predictions are compared to numerical simulations of scatter for parameters of recent experiments.
Abstract: The noise spectrum from which stimulated Brillouin scatter grows has two sources in laser fusion plasmas; a broadband source due to ion‐acoustic fluctuations, and a line source, usually much larger, which is the nonabsorbed light returning from the plasma critical surface. We give a theoretical description of stimulated Brillouin backscatter when the fluctuation source may be neglected and the scatter grows exclusively from the nonabsorbed light. Gradients of background density, velocity, and temperature are allowed. Theoretical predictions are compared to numerical simulations of scatter for parameters of recent experiments. It is found that stimulated Brillouin scatter can be greatly enhanced by the presence of a critical surface and that it can become an important part of the total energy balance.

81 citations

Journal ArticleDOI
TL;DR: In this paper, the authors measured the Brillouin gain spectra in two 250m-long single-mode fibers with GeO/sub 2/-doped core/pure-silica cladding (fiber A) and pure-Silica core/F-doped cladding(fiber B) at temperatures ranging from -40 to +60 degrees C at a wavelength of 1.32 mu m.
Abstract: Brillouin gain spectra in two 250-m-long single-mode fibers with GeO/sub 2/-doped core/pure-silica cladding (fiber A) and pure-silica core/F-doped cladding (fiber B) were measured at temperatures ranging from -40 to +60 degrees C at a wavelength of 1.32 mu m. The temperature coefficients of Brillouin frequency shift were found to be 1.17 and 1.33 MHz/ degrees C for fibers A and B, respectively. Temperature coefficients of Brillouin gain bandwidth were found to be -0.12 and -0.10 MHz/ degrees C. These measurements provide useful information for applications of stimulated Brillouin scattering. >

81 citations

Journal ArticleDOI
TL;DR: In this paper, the authors analyze fluctuation effects in a two-dimensional electron system on a square lattice in the vicinity of a Pomeranchuk instability with $d$-wave symmetry, using a phenomenological model which includes interactions with a small momentum transfer.
Abstract: A metallic electron system near an orientational symmetry breaking Pomeranchuk instability is characterized by a ``soft'' Fermi surface with enhanced collective fluctuations. We analyze fluctuation effects in a two-dimensional electron system on a square lattice in the vicinity of a Pomeranchuk instability with $d$-wave symmetry, using a phenomenological model which includes interactions with a small momentum transfer only. We compute the dynamical density correlations with a $d$-wave form factor for small momenta and frequencies, the dynamical effective interaction due to a fluctuation exchange, and the electron self-energy. At the quantum critical point the density correlations and the dynamical forward scattering interaction diverge with a dynamical exponent $z=3$. The singular forward scattering leads to large self-energy corrections, which destroy Fermi liquid behavior over the whole Fermi surface except near the Brillouin zone diagonal. The decay rate of single-particle excitations, which is related to the width of the peaks in the spectral function, exceeds the excitation energy in the low-energy limit. The dispersion of maxima in the spectra flattens strongly near those portions of the Fermi surface which are remote from the zone diagonal. The contribution from classical fluctuations to the self-energy spoils $(\ensuremath{\omega}∕T)$ scaling in the quantum critical regime.

81 citations

Journal ArticleDOI
TL;DR: In this article, the Brillouin spectra of binary and ternary silicate glasses were investigated and absolute values for the Pockets coefficients p12 and p44 and (p11 and p12) were calculated from the measured spectra.
Abstract: The Brillouin spectra of binary and ternary silicate glasses were investigated and absolute values for the Pockets coefficients p12 and p44 and (p11 – p12) were calculated from the measured spectra The results were interpreted as to the density and refractive index dependence of the Pockels coefficients in terms of the theoretical treatments by Carleton, Mueller and Sipe From the measured p12 and p44 values the quantity (ϱ∂ϵ/∂p), the change of the dielectric constant with respect to density, was calculated and compared with (ϱ∂ϵ/∂ϱ) evaluated from the Lorentz-Lorenz equation, Drude equation and the Carleton model The Lorentz-Lorenz and Drude equations overestimated the magnitude of (ϱ∂ϵ/∂ϱ), while the Carleton model with its two limiting cases set upper and lowe bounds to (ϱ∂ϵ/∂ϱ) From the (ϱ∂ϵ/∂ϱ) results the strain polarizability constant (λ0) was determined and its physical significance discussed In general, the alkali-oxide concentration dependence of the Pockels coefficients of various silicate glasses has been measured and qualitatively explained by several existing theoretical formulations

81 citations


Network Information
Related Topics (5)
Band gap
86.8K papers, 2.2M citations
91% related
Magnetization
107.8K papers, 1.9M citations
91% related
Quantum dot
76.7K papers, 1.9M citations
90% related
Thin film
275.5K papers, 4.5M citations
88% related
Photoluminescence
83.4K papers, 1.8M citations
88% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023430
2022957
2021463
2020543
2019568
2018587