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

Upconversion fluorescence imaging of HeLa cells using ROS generating SiO2-coated lanthanide-doped NaYF4 nanoconstructs

Inorganic nanomaterials able to generate reactive oxygen species (ROS) are promising components for modern medical applications. Activated by near-infrared light, up-converting beta-NaYF4 doped with Er3+ - Yb3+ and Tm3+- Yb3+ pair ions nanoparticles (UCNPs ...

2017

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

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

M-Plane GaN/InAlN Multiple Quantum Wells in Core-Shell Wire Structure for UV Emission

Jean-François Carlin, Nicolas Grandjean, Raphaël Butté, Georg Rossbach

We report on the epitaxial growth of high-quality core-shell nonpolar m-plane GaN/InAlN multiple quantum wells (MQWs) on the sidewall facets of c-oriented hexagonal GaN wires. Pseudomorphic growth without generation of threading dislocations has been estab ...

Amer Chemical Soc2014

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

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

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

Thermal decay of ArF-excimer-laser fabricated fiber Bragg gratings in Bi-Al-doped optical fibers

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

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

Photosensitivity and stress changes of Ge-free Bi-Al doped silica optical fibers under ArF excimer laser irradiation

Hans Georg Limberger, Christian Ban

The photosensitivity of germanium free Bi-Al-doped silica fibers with different bismuth concentrations was investigated using ArF excimer laser radiation at 193 nm and fiber grating formation. For the fiber with the highest bismuth concentration maximum re ...

Optical Society of America2011

Intrinsic Emittance Reduction of an Electron Beam from Metal Photocathodes

Christoph Peter Hauri

Electron beams in modern linear accelerators are now becoming limited in brightness by the intrinsic emittance of the photocathode electron source. Therefore it becomes important for large scale facilities such as free electron lasers to reduce this fundam ...

2010

Photosensitivity and luminescence of chromium and bismuth doped fibers

Christian Ban

Optical fiber materials with broad-band gain in the visible or in the telecommunication window are of great interest for optical communication or the biomedical domain in order to built integrated tunable lasers, amplifiers, ultra-short pulse lasers, or br ...

EPFL2009

Fiber bragg gratings in polymer optical fibers

Nico Gérard Harbach

Polymer optical fibers (POF) have received increased attention in recent years in the fields of data communication and sensing applications. The lower cost and higher flexibility are the main advantages of POF compared to silica fibers and make them intere ...

EPFL2008

Laser-induced stress changes in optical fibers

Florian Dürr

The precise determination of residual stress profiles in optical fibers allows drawing conclusions about radiation-induced density-changes of the fibers doped core glass. The corresponding index changes partially contribute to the phenomenon of photosensit ...

EPFL2005