IPG Photonics

About: IPG Photonics is a based out in . It is known for research contribution in the topics: Laser & Fiber laser. The organization has 903 authors who have published 1241 publications receiving 63339 citations.

High power laser system with multiport circulator

Abstract: A high power (HP) fiber circulator is configured with a case enclosing a plurality of optical components which are arranged so as to define multiple ports. The fiber circulator further includes a plurality of launching and receiving fiber components each of which has spliced delivery and pigtailed passive fibers selectively coupling a HP input signal into and receiving a HP output signal from respective input and output ports. The passive fibers of each fiber component have respective protective coatings spaced from one another and each covering the cladding of the fibers. A light stripper, extending between the protective coatings, is operative to substantially remove cladding- supported light from one of the passive fibers before it reaches the protective coating of the other passive fiber. At least one of the ports includes a wavelength selective component configured to direct the HP input light beam along the desired path between the ports and including a fiber Bragg grating, volume Bragg grating or a combination of these.

Analysis of strong-motion S wave polarization of the 15 October 1979 Imperial Valley earthquake

Abstract: This article illustrates the use of near-source S -wave polarization analyses for constraining some rupture parameters of large earthquakes, in the particular case of the 1979 Imperial Valley mainshock. The ten SMA1 strong-motion records closest to the source have been studied in the 1 to 3-Hz frequency range. The records were first corrected following the analysis of Zollo and Bernard (1989), from some anisotropy that produced strong S splitting at a few sites. The rotation of the S polarization with time at most of the sites was then interpreted in terms of the northwestward propagation of the rupture. We assumed a constant focal mechanism on the fault plane (vertical strike slip). The polarization data and the absolute times at some stations allowed the identification of a set of subsources. Their location in space and time (assuming a depth of 8 km) provided a mean rupture velocity of 3.1 km/sec (±0.25 km/sec), i.e., 90% of the shear velocity. The high-frequency radiation (3 Hz) during most of the rupture thus is very likely to have been generated about 1 sec before the beginning of the low-frequency radiation (0.5 to 1 Hz) studied by Archuleta (1984). The final rupture model fits the S -polarization history well at most sites; it also constrains the anisotropy characteristics of the sediments under some sites, in particular EM0, where it is consistent with the alignment of vertical cracks in the NS stress field. Applying such a method to other earthquakes requires a careful selection of the distance and frequency range. In particular, the effect of perhaps pervasive ubiquitous anisotropy in the upper crust must be taken into account, which may require the analysis of aftershock records at the same sites.

>1.5kW narrow linewidth CW diffraction-limited fiber amplifier with 40nm bandwidth

Abstract: Operation from 1030nm to 1070nm in single narrow linewidth fiber amplifier with >1.5kW output power is presented. The fiber amplifier has up to 3m output cable for <15GHz linewidth. The fiber amplifier in the ruggedized compact modular package has 40% wall-plug efficiency. The spectral dependence of higher order mode instability threshold is described.

Impact of glass density on the green emission and NBOHC formation in silica glass: A combined high pressure and 2.5 MeV electron irradiation

Abstract: Macroscopic Suprasil F300 type silica glasses densified under high pressure and high temperature were irradiated with 2.5 MeV electrons. This paper focuses on the point defects generation in those densified silica glasses. We demonstrated that the unattributed 540 nm emission band was clearly enhanced when the irradiated glasses exhibit a higher density either initially generated by high pressure cycle or by irradiation at high dose (> 3 GGy). The spectral shape of the emission band related to Non Bridging Oxygen Hole Center (NBOHC) is also modified with a broader FWHM due to an additional contribution near 610 nm indicating a larger distribution of NBOHC species in these densified glasses.