Gain and noise figure of a double-pass waveguide amplifier based on Er/Yb-doped phosphate glass

A waveguide amplifier is fabricated by Ag+-Na+ two-step ion exchange on Er/Yb-doped phosphate glass. The spectroscopic performance of glass and the properties of channel waveguide are characterized. A double-pass configuration is adopted to measure the gain and noise figure (NF) of the waveguide amplifier, and the comparison of gain and NF for the single and double-pass configuration of the waveguide amplifier is presented. The results show that the double-pass configuration can make the gain increase from 8.8dB (net gain 2.2dB/cm) of the single-pass one to 14.6 dB (net gain 3.65 dB/cm) for small input power at 1534 nm, and the NF are all lower than 5.5dB for both the configurations.

Waveguide lasers in Er:Yb-doped phosphate glass fabricated by femtosecond laser writing

Advanced waveguide lasers, operating both in continuous wave and pulsed regimes, have been realized in an active phosphate glass by direct writing with femtosecond laser pulses. Stable single mode operation was obtained; the laser provided more than 50 m W in single longitudinal and transverse mode operation with 21% slope efficiency. Furthermore, by combining a high gain waveguide and an innovated fiber-pigtailed saturable absorber based on carbon nanotubes, a mode-locked ring laser providing transform limited 1.6 ps pulses was demonstrated. © 2007 IEEE.

Mode-locked and single-longitudinal-mode waveguide lasers fabricated by femtosecond laser pulses in Er:Yb-doped phosphate glass

Mode-locked and single-longitudinal-mode waveguide lasers, manufactured by femtosecond laser writing in Er-Yb-doped phosphate glasses, are presented. Transform-limited 1.6-ps pulses and a cw output power exceeding 50 mW have been obtained in the two regimes. © 2007 Optical Society of America.

Mode-locked and single-longitudinal-mode waveguide lasers fabricated by femtosecond laser pulses in Er: Yb-doped phosphate glass

Mode-locked and single-longitudinal-mode waveguide lasers, manufactured by femtosecond laser writing in Er-Yb-doped phosphate glasses, are presented. Transform-limited 1.6-ps pulses and a cw output power exceeding 50 mW have been obtained in the two regimes. © 2007 Optical Society of America.

Gibbs’ free energies of formation of Cu2Ln2O5 (Ln = Tb, Dy, Er, Yb) compounds

The standard Gibbs' free energies of formation of compounds of type Cu2L%05 (Ln = Tb,Dy,Er,Yb) were measured using the solid state cell in the temperature range of 970 to 1323 K For formation of Cu2L?O5 compounds from their binary component oxides according to the reaction 2 CUO (s) + L%03 (s) -, Cu,,L%05 (s),the Gibbs' free energy changes can be represented by the following equations:AGO = 13 080 - 13.70 'I" (+80) J mol-' (Ln = Tb)AGq = 11 480 - 13.51 T (260) J mol-I (Ln = Dy)AGO = 10 750 - 13.99 T (260) J mol-I (Ln = Er)AGO = 9 920 - 13.90 T (260) J mol-' (Ln = Yb) Since formation of the compounds is endothermic, the compounds become thermodynamically unstable with respect to their component oxides below 955 K for Cu2Tb205, 850 K for Cu2Dy205, 768 K for Cu2Er205 and 714 K for Cu2Yb2OS When the oxygen partial pressure over Cu2L%05 is lowered, they decompose according to the scheme, 2 CU,L%O, (s) -r 2 L%03 (s) +2 cu20 (s) + 02(g)The equilibrium chemical potentials of oxygen corresponding to the dissociation reactions are computed from the emf data and auxiliary information on Cu20 and CuO. The computed decomposition temperatures at an oxygen partial pressure of 5.0 x ld Pa are compared with those obtained directly from combined thermogravimetric (TGA) and differential thermal analyses (DTA).The free energy, enthalpy and entropy of formation of Cu2Ln205 compounds show systematic variation with the ionic radius of the trivalent lanthanide ion. The trends obtained in this study are compared with information available in the literature. The staZbility of Cu2Ln205 compounds increases with the decrease in ionic radii of the ~ n ion~. +

H[DEHP]从不同介质中萃取稀土（III）(Sc、Y、Ho、Er、Yb、Lu)及Fe(III)、Zn(II)的机理

本文分另研究了H[DEHP]从不同酸性介质中萃取稀土（III）(Sc、Y、Ho、Er、yb、Lu)及Fe(III)、Zn(II)的机理及性能。一、H[DEHP]从 H_2SO_4介质中萃取Sc(III)的机理 1. H[DEHP]萃取H_2SO_4及其机理 2. H[DEHP]萃取Sc(III)的机理，用斜率法和饱和法确定了H[DEHP]的正庚烷溶液从H_2SO_4溶液中萃取Sc_2(SO_4)_3的机理及萃合物组成。研究表明，H[DEHP]萃取Sc(III)在高、低两种酸度范围内存在着两种不同的萃取机理。二、H[DEHP]从HCl介质中萃取Ln(III)和Fe(III)的性能及H[DEHP]萃取Ln(III)的机理研究了H[DEHP]的正庚烷溶液从HCl介质中萃取稀土（III）(Sc、Y、Ho、Er、Yb、Lu)和Fe(III)的性能，得出H[DEHP]在相同条件下萃取以上各金属离子的顺序是：Sc(III)>Fe(III)>Lu(III)>Yb(III)>Er(III)>Y(III)>Ho(III), 并计算了各金属离子之间的分离因素（β）。文中还讨论了Sc(III)、Fe(III)、Lu(III)之间的分离以及重稀土离子间的萃取分离，同时与相同实验条件下HEH[EHP]的萃取性能进行了比较，为新的萃取体系提供了一些参数。三、H[DEHP]从不同介质中萃取Fe(III)的机理，研究了H[DEHP]的正率烷溶液从Hcl介质中和H[DEHP]的正庚烷溶液从H_2SO_4介质中萃取Fe(III)的平衡规律；用斜率法、饱和法以及IR和NMR谱等讨论了低酸度下的萃取机理。四、H[DEHP]萃取Zn(II)的机理，研究了H[DEHP]的正率烷溶液从Hcl介中萃取Zn(II)的平衡，利用斜率法、饱和法及SR、NMR谱等讨论了低Hcl浓度下的萃取机理。

Syntheses and crystal structures of bis(tetrahydrofurfurylindenyl) lanthanocene chlorides (C4H7OCH2C9H6)(2)LnCl (Ln = Nd, Sm, Dy, Ho, Er, Yb)

Reaction of anhydrous lanthanide trichlorides with tetrahydrofurfuryl indenyl lithium in THF afforded bis(tetrahydrofurfurylindenyl) lanthanocene chlorides complexes (C4H7OCH2C9H6)(2) LnCl, Ln = Nd (1), Sm (2), Dy (3), Ho (4), Er (5), Yb (6). The X-ray crystallographic structures of all the six complexes were determined and these indicate that they are unsolvated nine-coordinate monomeric complexes with a trans arrangement of both the sidearm and indenyl rings in the solid state. They belong to the same crystal system (orthorhombic) and space group (P2(1)2(1)2(1)) with the same structure. Especially, they are more stable to air and moisture than the corresponding unsubstituted indenyl lanthanide complexes.

Microwave Dielectric Properties of RETiTaO6 (RE = La, Ce,Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Er, Yb, Al, and In) Ceramics

Microwave dielectric ceramics based on RETiTaO6 (RE = La, Cc, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Er, Yb, Al, and In) were prepared using a conventional solid-state ceramic route. The structure and microstructure of the samples were analyzed using x-ray diffraction and scanning electron microscopy techniques. The sintered samples were characterized in the microwave frequency region. The ceramics based on Ce, Pr, Nd, Sm, Eu, Gd, Tb, and Dy, which crystallize in orthorhombic aeschynite structure, had a relatively high dielectric constant and positive T f while those based on Ho, Er, and Yb, with orthorhombic euxenite structure, had a low dielectric constant and negative Tf. The RETiTaO6 ceramics had a high-quality factor. The dielectric constant and unit cell volume of the ceramics increased with an increase in ionic radius of the rare-earth ions, but density decreased with it. The value of Tf increased with an increase in RE ionic radii, and a change in the sign of Tf occurred when the ionic radius was between 0.90 and 0.92 A. The results indicated that the boundary of the aeschynite to euxenite morphotropic phase change lay between DyTiTaO6 and HoTiTaO6. Low-loss ceramics like ErTiTaO6 (Er = 20.6, Qxf = 85,500), EuTiTaO6 (Er = 41.3, Qxf = 59,500), and YTiTaO6 (Er = 22.1, Q„xf = 51,400) are potential candidates for dielectric resonator applications

Up-converter nanophosphor Y2O2S:Er,Yb aminofunctionalized containing or not spherical silica conjugated with BSA

This work reports on the study of the nanophosphor. Y2O2S:Er(2%),Yb(1%) obtained from polymeric resin to be evaluated as fluorescent label with Suitable features to conjugate with bio-molecules for bioassay up-converting phosphor technology (UPT) application A conjugation protocol between bovine serum albumin (BSA) and the aminofunctionalized nanophosphor containing or not spherical silica was established UV-vis results indicated an effective conjugation between nanophosphor particles and the protein up-conversion measurements under 980 nm excitation performed for samples before and after aminofunctionalization showed that nanophosphor particles luminescence features keep unchanged in all cases All results suggest that the adapted protocol is feasible to provide a nanoparticle-protein effective conjugation preserving nanophosphor optical features The presence of spherical silica can be considered advantageous to increase conjugation efficiency Therefore. the developed procedure is applicable for future conjugations between the chosen nanophosphor and the streptavidin protein chat takes part in the well known self-recognition system avidin-biotin. (C) 2009 Elsevier B.V All rights reserved.

Morphological and luminescent studies on nanosized Er, Yb-Yttrium oxide up-converter prepared from different precursors

In this paper, we report luminescent and morphological studies with yttrium oxide samples doped with ytterbium and erbium. The samples were prepared by the combustion method and also from different precursors: oxalate, basic carbonate and polymeric resin. All powders were identified Lis being an yttrium oxide with a C-form structure, independent of the employed precursor. From mean crystallite size measurements, it was verified that oxides prepared through the polymeric precursor and combustion methods lead to the smallest crystallite size. Particle shape and size were investigated by SEM and TEM, and showed that both the oxalate precursor and the combustion methods do not provide oxide materials of suitable shape or size, on the other hand. The basic carbonate and polymeric precursors resulted in spherically shaped particles with an average diameter of 90 and 15 run. respectively, Upon 980 run diode laser excitation, green and red emission lines were detected for all samples and were assigned to the H-2(11/2) S-4(3/2) -> I-4(15/2) and (4)Fg(9/2) -> 4I(15/12) transitions, respectively. Such transitions are characteristic for Er3+ and result from energy transfer from Yb3+ energy levels, F-2(7/2) -> F-2(5/2). A relationship between the decrease in the mean crystallite size and the enhancement in red emission was also established as well as the influence of the presence of a high percentage of Yb-3 Both factors promote ET from Yb3+ (F-2(5/2)) to Er3+ (I-4(11/2)). (c) 2004 Elsevier B.V. All rights reserved.

Radiative Behaviour of Gd2O3:Er/Yb nanoparticles under near infrared illumination

Upconverting nanoparticles have attracted much attention in science recently, specifically in view of medical and biological applications such as live imaging of cell temperatures or cancer treatment. The previously studied system of gadolinium oxide nanorods co-doped with erbium and ytterbium and decorated with different number densities of gold nanoparticles has been studied. So far, these particles have been proven as efficient nanothermometers in a temperature range from 300 up to 2000 K. In this work, a more detailed study on the morphological and radiative behaviour of these particles has been conducted. It was found that the laser power threshold for the onset of the black body radiation decreases strongly with the increase in the gold concentration. The temperature of the onset itself seems to remain approximately constant. The heating efficiency was determined to increase significantly with the gold concentration. The morphological study revealed that the temperature at the black body radiation threshold was not enough to induce any significant transformation in neither the nanorods nor the gold nanoparticles, as was expected from comparison with literature. However, significant changes in radiative properties and the morphology were detected for powders that underwent strong laser heating until the emission of brightly visible black body radiation.