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Showing papers by "IPG Photonics published in 1990"

Journal Article•DOI•
Core-mantle topographic torque: a spherical harmonic approach and implications for the excitation of the Earth's rotation by core motions

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J. Hinderer, H. Legros, Dominique Jault1, J. L. Le Mouël1•
IPG Photonics1
01 Jan 1990-Physics of the Earth and Planetary Interiors
TL;DR: In this article, a general formulation of the topographic torque is proposed with the help of a development in spherical harmonics of the pressure and shape, and various implications of this coupling mechanism are discussed according to the symmetry properties of the dynamic pressure field at the core surface and the distribution of topographical deviations of the core mantle boundary inferred from seismology.

49 citations

Proceedings Article•DOI•
Nonlinear Inversion of Seismograms: State of the Art

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Albert Tarantola1, Edward Craset2, Michael Jervis1, Zvi Konen3, Jonas Lindgren1, Klaus Mosegaard4, Mark Noble •
IPG Photonics1, Montana Tech of the University of Montana2, Elf Aquitaine3, University of Copenhagen4
01 Jan 1990-Seg Technical Program Expanded Abstracts

18 citations

Patent•
Optical interconnection network

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David William Smith1, Cassidy Stephen Anthony, Peter Healey•
IPG Photonics1
05 Feb 1990
TL;DR: An optical interconnection network comprises an optical bus (60) formed by a D-fibre (62) embedded in a thermoplastic substrate (64) with the flat of the D-bibre flush with the top surface of the substrate as mentioned in this paper.
Abstract: An optical interconnection network comprises an optical bus (60) formed by a D-fibre (62) embedded in a thermoplastic substrate (64) with the flat of the D-fibre (62) flush with the top surface of the substrate. A module (70) similarly constructed is dimensioned to be a push fit in a wall structure (65) formed on the substrate (64) with the fibres (72) and (62) in a position to evanescently couple optical signals from one fibre to the other.

13 citations

Patent•
Optical time domain relectometry with optical amplifier for extended range and/or sensitivity

[...]

Blank Lutz Christian1, David M. Spirit2•
IPG Photonics1, BT Group2
22 Jun 1990
TL;DR: In this paper, a method for increasing the optical measurement range in optical time domain reflectometers in which a fibre laser amplifier is used to amplify the optical time-domain reflectometer pulses launched into a waveguide is presented.
Abstract: Apparatus and a method for increasing the optical measurement range in optical time domain reflectometers in which a fibre laser amplifier is used to amplify the optical time domain reflectometer pulses launched into a waveguide. This apparatus and method have particular usefulness for branched local networks. The signal returning to the optical time domain reflectometer is amplified as well as the outbound signal.

6 citations