Anne-Marie Jurdyc

Spectroscopic properties, concentration quenching, and laser investigations of Yb 3+ -doped calcium aluminosilicate glasses

“Calcium aluminosilicate” (CAS) and “low silica calcium aluminosilicate” (LSCAS) OH− free glasses have demonstrated a good potential for solid-state laser media and luminophore hosts due to good thermal, optical, and mechanical properties. Some examples have already been shown with Nd3+, Er3+, Ce3+, and Ti3+ luminescent ions. In this work, Yb3+ rare-earth laser ions have been introduced into the two series of CAS and LSCAS glasses melted at 1600 °C in a vacuum furnace and have been optically characterized and compared. Special attention has been devoted to both structural characterization in relationship with spectroscopic properties and concentration quenching phenomenon in relationship with laser parameters. Laser measurements at 1037 nm have been successfully performed under laser diode pumping.

Erbium emission properties in nanostructured fibers

A new route was recently proposed to modify some spectroscopic properties of rare-earth ions in silica-based fibers. We had shown the incorporation of erbium ions in amorphous dielectric nanoparticles, grown in fiber preforms. Here we present the achieved stabilization of nanometric erbium-doped dielectric nanoparticles within the core of silica fibers. We present the nanoparticle dimensional characterization in fiber samples. We also show the spectroscopic characterization of erbium in preform samples with similar nanoparticle size and composition. This new route could have important potentials in improving rare-earth-doped fiber amplifiers and laser sources.

Optical properties of thulium-doped chalcogenide glasses and the uncertainty of the calculated radiative lifetimes using the Judd-Ofelt approach

A brief description of the basic spectroscopic properties of Tm3+-doped 20Ge-5Ga-10Sb-65S (GeGaSbS) glass is presented. Spontaneous-emission probabilities, radiative lifetimes, branching ratios, and quantum efficiency of Tm3+ in GeGaSbS glass are evaluated by use of Judd-Ofelt theory. Lifetime measurements are carried out at room and low temperatures. A large difference of the lifetime values occurs between the theoretical and experimental results. McCumber and Ladenburg-Funchtbauer techniques are used for the emission cross-section determinations. Discrepancies appear between these two techniques. Hypotheses about the presence of the diffusion-limited relaxation process are applied for explanations.

Inhomogeneous and homogeneous linewidths in Er3+-doped chalcogenide glasses

Abstract The erbium 4 I 13/2 – 4 I 15/2 transition around 1.5 μm is of prim interest for telecommunications and depends on the erbium ions surrounding. In glasses, the broadening of a transition comes from two contributions: inhomogeneous (due to the disorder) and homogeneous (due to the electron phonon interaction) broadening. Resonant Fluorescence Line Narrowing (RFLN) is a useful tool to separate this two parameters. We will show in this paper that the 4 I 13/2 – 4 I 15/2 transition in chalcogenide glass (GeGaSSb) presents a strong homogeneous character and a smaller inhomogeneous contribution compared to aluminosilicate and fluoride glasses. Consequences on gain saturation will also be discussed.

Submicrosecond fluorescence dynamics in erbium-doped silicon-rich silicon oxide multilayers

The energy transfer process between amorphous silicon nanoparticles and erbium ions in Er-doped silicon-rich silicon oxide is investigated by fluorescence dynamics measurements. A fast decay is observed in the wavelength range of the radiative relaxation of erbium excited ions at 1.53 μm. Alternatively to a previous interpretation, we assign this fast decay to emission of deep traps induced by Si-based sensitizers of Er3+ ions, which emit in the visible and the infrared region.

Optical properties of stabilized Dy3+-doped sulfide glasses for 1.3-μm amplification

Sulfide glasses based on GeGaS are stabilized by the addition of a fourth element: antimony. They show very weak crystallization upon heating as compared to standard GeGaS glass. Because of the low phonon energy inherent in sulfide glasses, the 1.3 micrometers emission of Dy3+ ions can be observed. This transition is characterized in terms of emission cross-section and quantum efficiency. Refractive indices are measured for various concentrations of cesium halides in standard GeGaS glass.

Revisiting literature observations on photodarkening in Yb3+doped fiber considering the possible presence of Tm impurities

Ytterbium (Yb) doped fiber lasers are known to be affected by the creation of color centers during lasing (so-called photodarkening (PD)). In a previous work, this defect creation was investigated from a spectroscopic point of view, showing the presence of traces (ppb) of thulium (Tm) in the Yb doped fiber. It was shown that Tm has a strong impact on the defect creation process involved in PD. In this paper, we compare the results from the literature with our Tm hypothesis, without finding any contradiction. Moreover, this hypothesis can be an explanation for the discrepancies in the literature.

Tunable red-light source by frequency mixing from dual band Er/Yb co-doped fiber laser

We report an all solid state laser device producing tunable dual wavelength emission in the near IR region (1060nm, and 1550 nm) by use of an Er/Yb co-doped fiber. Generation of continuous-wave radiation around 630 nm is then demonstrated by extra-cavity sum frequency mixing in a Periodically Poled Lithium Niobate (PPLN) crystal. Quasi phase matching conditions are obtained over 7 nm to generate tunable coherent light in the red spectral range.

Chalcogenide waveguide for IR optical range

Due to remarkable properties of the chalcogenide glasses, especially sulphide glasses, amorphous chalcogenide films should play a motivating role in the development of integrated planar optical circuits and their components. This paper describes the fabrication and properties of optical waveguides of pure and rare earth doped sulphide glass films prepared by two complementary techniques: RF magnetron sputtering and pulsed laser deposition (PLD). The deposition parameters were adjusted to obtain, from sulphide glass targets with a careful control of their purity, layers with appropriate compositional, morphological, structural characteristics and optical properties. These films have been characterized by micro-Raman spectroscopy, atomic force microscopy (AFM), X-ray diffraction technique (XRD) and scanning electron microscopy (SEM) coupled with energy dispersive X-ray measurements (EDX). Their optical properties were measured thanks to m-lines prism coupling and near field methods. Rib waveguides were produced by dry etching under CF4, CHF3 and SF6 atmosphere. The photo-luminescence of rare earth doped GeGaSbS films were clearly observed in the n-IR spectral domain and the study of their decay lifetime will be presented. First tests were carried out to functionalise the films with the aim of using them as sensor.

Surface-enhanced Raman scattering of amorphous TiO2 thin films by gold nanostructures: Revealing first layer effect with thickness variation

In this paper, amorphous titanium dioxide (TiO2) thin films have been deposited on a commercially available Klarite substrate using the sol-gel process to produce surface-enhanced Raman scattering (SERS). The substrate consists of square arrays of micrometer-sized pyramidal pits in silicon with a gold coating. Several thin TiO2 layers have been deposited on the surface to study the influence of film thickness. Ultimately, we obtained information on SERS of an amorphous TiO2 layer by gold nanostructures, whose range is less than a few nanometers. Mechanisms responsible for the enhancement are the product of concomitant chemical and electromagnetic effects with an important contribution from plasmon-induced charge transfer.