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.

The MU-RAY project: Summary of the round-table discussions

Abstract: The MU-RAY project has the challenging aim of performing muon radiography of the summit cone of Mt. Vesuvius. The muon telescopes developed for this purpose will be available for the radiography of other volcanoes, in particular Stromboli. The scientific goals, the strategy for their implementation and the baseline detector design are discussed in detail. A tentative time schedule for the project is drawn.

In situ high-temperature (→ 2100 K) XAFS and anharmonicity

Abstract: High-temperature (up to 2100 K) XAFS data in the energy-dispersive mode has been collected at Ga and Ge K-edges on a new type of micro-furnace (heating wire) that can run up to 3500 K. Another advantage is the fast data collection time (few seconds per spectra). Data were collected in a variety of Ga- and Ge-oxide compounds. At Ge-K edge, [4]Ge4+ polyhedra shows a weak anharmonicity, related to the high GeO bond strength in those compounds. In contrast, [6]Ge4+ polyhedra has a slightly anharmonic behaviour, but much smaller compared to more weaker bonds, like in [4, 6]Ga2 3+O3 or olivine-[6]Ni22+ SiO4. The high-temperature, time-resolved analysis of a [6] Ge → [4] Ge coordination change can also be followed in situ, as well as the melting of these high temperature phases.

Assembly for measuring optical signal power in fiber lasers

Abstract: A fiber laser system is configured with a power measuring assembly surrounding a splice between two fibers. The power measuring assembly is operative to maintain the splice at a substantially constant splice temperature and shield the spliced fibers from external bending stresses so as to provide for power readings of the laser system at the splice independently from the influence of multiple variable external factors.

Laser diode array with fiber optic termination for surface treatment of materials

Abstract: Individually operable laser diodes in an array are associated with optical fibers for treatment of a material. Each laser diode has a generally Gaussian or similar profile. A guide block receives optical fiber terminal distal ends and enables irradiation of a surface for treatment with overlapping profiles. A control system controls individual laser diodes to achieve desired illumination profiles for a given process. The process is performed in a suitable environment which may include a vacuum system, controlled gaseous environment, or in a doping medium such as a surface coating or even a liquid. Optional relay optics interposed between the terminal distal ends and the treatment material allows distant relaying and reimaging. An optical isolator assembly may be interposed between the relay optics and the treatment material. The system and related methods allow direct irradiation from laser diodes to treat materials.

Sensitivity of a phase-sensitive optical time-domain reflectometer with a semiconductor laser source

Abstract: In the present paper we perform, for the first time, an analysis of the average sensitivity of a coherent phase-sensitive optical time-domain reflectometer (phase-OTDR) with a semiconductor laser source to external actions. The sensitivity of this OTDR can be defined in a conventional manner via average SNR at its output, which in turn is defined by the average useful signal power and the average intensity noise power in the OTDR spatial channels in the bandwidth defined by the OTDR sampling frequency. The average intensity noise power is considered in detail in a previous paper. In the current paper we examine the average useful signal power at the output of a phase-OTDR. The analysis of the average useful signal power of a phase-OTDR is based on the study of a fiber scattered-light interferometer (FSLI) which is treated as a constituent part of a phase- OTDR. In the analysis, one of the conventional phase-OTDR schemes with a rectangular dual-pulse probe signal is considered. The FSLI which corresponds to this OTDR scheme has two scattering fiber segments with additional time delay, introduced between backscattered fields. The average useful signal power and the resulting average SNR at the output of this FSLI are determined by the degree of coherence of the semiconductor laser source, the length of the scattering fiber segments, and by the additional time delay between the scattering fiber segments. The average useful signal power characteristic of the corresponding phase-OTDR is determined by analogous parameters: the source coherence, the time durations of the parts constituting the dual-pulse, and the time interval which separates these parts. In the paper an expression for the average useful signal power of a phase-OTDR is theoretically derived and experimentally verified. Based on the found average useful signal power of a phase-OTDR and the average intensity noise power, derived in the previous paper, the average SNR of a phase-OTDR is defined. Setting the average signal SNR to 1, at a defined spectral band the minimum detectable external action amplitude for our particular phase-OTDR setup is determined. We also derive a simple relation for the average useful signal power and the average SNR which results when making the assumption that the laser source coherence is high. The results of the paper can serve as the basis for further development of the concept of phase-OTDR sensitivity.