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Hans Georg Limberger

Cette personne a quitté l’EPFL

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Publications associées (41)

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An experimental-numerical investigation of hydrothermal response in adhesively bonded composite structures

Véronique Michaud, Hans Georg Limberger, John Botsis, Georgios Violakis, Roohollah Sarfaraz Khabbaz, Luis Pablo Canal Casado

Water absorption and thermal response of adhesive composite joints were investigated by measurements and numerical simulations. Water diffusivity, saturation, swelling, and thermal expansion of the constituent materials and the joint were obtained from gra ...

Elsevier2015

Polarization microscopy by use of digital holography: application to optical- fiber birefringence measurements

René Salathé, Hans Georg Limberger, Pierre Marquet, Christian Depeursinge, Tristan Colomb, Etienne Cuche, Florian Dürr

We present a digital holographic microscope that permits one to image polarization state. This technique results from the coupling of digital holographic microscopy and polarization digital holography. The interference between two orthogonally polarized re ...

2005

Monitoring strain gradients in adhesive composite joints by embedded fiber Bragg grating sensors

Véronique Michaud, Hans Georg Limberger, John Botsis, Georgios Violakis, Roohollah Sarfaraz Khabbaz, Luis Pablo Canal Casado

The adhesive bonding of composite materials can be applied to assemble light-weight structures for aeronautical applications. However, the application of adhesive bonds in primary load-bearing structures is limited by the lack of adequate techniques to mon ...

Elsevier2014

Ultrawide bandwidth wavelength monitor based on a pair of tilted fiber Bragg gratings

René Salathé, Hans Georg Limberger, Yann Tissot-dit-Sanfin

A wavelength monitor based on a pair of tilted fiber Bragg gratings is reported. The monitor exhibits a subpicometer wavelength selectivity over a broad wavelength range (> 30 nm), and a low insertion loss (< 1 dB) for laser light with polarization matchin ...

Institute of Electrical and Electronics Engineers2007

In situ strain and temperature monitoring of adaptive composite material

René Salathé, Véronique Michaud, Hans Georg Limberger

An optical fiber sensor is designed to simultaneously measure strain and temperature in an adaptive composite material. The sensor is formed by splicing two fiber Bragg gratings (FBGs) close to each other, which are written in optical fibers with different ...

SAGE Publications2006

Distributed strain measurements using fiber Bragg gratings in small-diameter optical fiber and low-coherence reflectometry

Hans Georg Limberger, John Botsis, Dragan Coric, Marco Lai

Optical low coherence reflectometry and fiber Bragg gratings written in small diameter (50 micrometer) optical fibers were used for measurements of non-homogenous internal strain fields inside an epoxy specimen with sub-grating length resolution. The resul ...

Optical Society of America2010

Thermal decay of UV Ar+ and ArF excimer laser fabricated Bragg gratings in SMF-28e and Bi-Al-doped optical fiber

Hans Georg Limberger, Georgios Violakis, Pouneh Saffari

Fiber Bragg Gratings were fabricated using a 193-nm-ArF-excimer laser with ac index changes of 0.6×10E-4 and 2.2×10E-4 in pristine and H2-loaded Bi-Al-SiO2 fibers. Thermal annealing of the FBGs was investigated using continuous isochronal annealing. ...

2012

Low loss wavelength monitor with sub-picometer resolution based on tilted fiber gratings

René Salathé, Hans Georg Limberger

A wavelength monitor based on a pair of tilted fiber Bragg gratings with low insertion loss (<1 dB) and sub-picometer wavelength resolution is reported. ...

IEEE2007

Fabrication of mode field converter in H2-loaded SMF-28e using CW-Ar+ laser

Hans Georg Limberger, Nandita Aggarwal, Georgios Violakis

We report on mode field diameter changes of -31% due to UV-induced core refractive index changes of

Optical Soc America, 2010 Massachusetts Ave Nw, Washington, Dc 20036 Usa2011

Annealing of UV Ar+ and ArF excimer laser fabricated Bragg gratings: SMF-28e fiber

Hans Georg Limberger, Georgios Violakis

Fiber Bragg gratings fabricated in pristine SMF-28e fibers using pulsed ArF-excimer and cw 244-nm Ar+ laser were annealed using tempering rates from 0.0038 to 0.25 K/s. Demarcation energy mapping allowed for the determination of the frequency factors and t ...

Optical Society of America2014

Photosensitivity and Luminescence Induced by ArF-Irradiation of Hydrogen Loaded Bi-SiO2 Fiber

Hans Georg Limberger, Georgios Violakis

Bi:SiO2 fiber drawn under oxidizing conditions shows ultra-low photosensitivity and no NIR luminescence under 1064 nm pumping. Hydrogen loading followed by ArF irradiation induced both. The increase of photosensitivity and the creation of luminescence cent ...

2013

UV-Photosensitivity of Germanium-free Bi-Al Silica Fibers

Hans Georg Limberger

Mean index changes up to 2.2 × 10-3 were demonstrated in hydrogen loaded germanium free Bi-Al-doped silica fibers. Tensile stress changes indicate a contribution of compaction to the total index change. ...

2010

Fabrication of Bragg gratings in microstructured and step index Bi-SiO2 optical fibers using an ArF laser

Hans Georg Limberger, Georgios Violakis

An ArF excimer laser was used to fabricate Bragg gratings in fibers with Bi-SiO2 core and microstructured or F-doped claddings without fiber presensitization. Average and modulated refractive index changes of 2.7 x 10(-4) and 1.0 x 10(-4) were induced in p ...

Optical Society of America2012

Formation of Bragg gratings in pristine SMF-28e fibre using cw 244-nm Ar+-laser

Hans Georg Limberger, Georgios Violakis

The formation of short Bragg gratings in SMF-28e non-hydrogen loaded pristine fibre using a cw Ar+ laser operating at 244 nm is reported. Mean refractive index changes >10-3 were obtained for a laser intensity of about 513 W/cm2 and a total dose of 5.9 MJ/ ...

Institution of Engineering and Technology2010

Editorial Foreword to The ECOC 2022 Special Issue

Hans Georg Limberger, Niels Quack, Rachel Grange

The European Conference on Optical Communications (ECOC) is one of the leading conferences in the field of optical communications and its related topics. The 48th edition took place from 18th-22nd September 2022 in Basel, Switzerland. The conference attrac ...

IEEE Institute of Electrical and Electronics Engineers2023

High resolution liquid-level sensor based on fiber Bragg gratings in attenuation fiber and optical low-coherence reflectometry

René Salathé, Hans Georg Limberger, Dragan Coric

2006

Dose dependence of luminescence increase in H2-loaded Bi-Al co-doped optical fibers by cw 244-nm and pulsed 193-nm laser irradiation

Hans Georg Limberger, Georgios Violakis

The near infrared luminescence is increased in H2-loaded Bi-Al co-doped optical fibers by irradiation of cw 244-nm or pulsed 193-nm laser light. The dose dependence is different for the two lasers. ...

Ieee2013

Infrared Luminescence Enhancement by UV-Irradiation of H2-loaded Bi-Al-doped Fiber

Hans Georg Limberger

ArF excimer laser irradiation of H2-loaded fibers increases the intensity of both the 1130 and 1390 nm fluorescence in Bi-Al-doped silica fiber by 18 dB and >16 dB. ...

2009

Stability of Fiber Bragg Gratings Fabricated Using UV Ar+ and ArF Excimer in Bismuth-Aluminum-co-Doped Silica Fibers

Hans Georg Limberger, Georgios Violakis

Continuous annealing of fiber Bragg gratings fabricated using cw and pulsed laser irradiation in Bi-Al-co-doped fibers of different concentrations show activation energy spectra linked to Bi-Al. Thermal stability maps were obtained by their analytical repr ...

2014

Fabrication of fiber Bragg gratings in 40 mm diameter low GeO2 silica fiber using cw-Ar+-laser

Hans Georg Limberger, Georgios Violakis

Mean index changes >10-3 were obtained in non-hydrogen-loaded 3% GeO2-doped silica fibers with a 9/40 micrometer core/cladding diameter using a cw 244-nm-Ar+-laser. Core stress changes are positive indicating a compaction contribution to the index change. ...

Optical Society of America2010