Characterization Of Yb Research Articles

Growth and Characterization of Yb: CALYGLO Crystal for Ultrashort Pulse Laser Applications

Yb:CALYGLO crystals with a dopant concentration of 5 at.% were successfully grown using the Czochralski method. The crystal samples were extensively studied to analyze their structure, room temperature and low temperature spectra, and laser properties. The highest absorption cross-section at 977 nm was calculated to be 1.83 × 10−20 cm2 for σ polarization and 5.32 × 10−20 cm2 for π polarization. Similarly, the emission cross-section was determined to be 1.38 × 10−20 cm2 at 980 nm for σ polarization and 2.28 × 10−20 cm2 at 981 nm for π polarization, with a full width at half maximum (FWHM) of 50.3 nm and 89.5 nm, respectively. The fluorescence lifetime of the 5 at.% Yb:CALYGLO crystal at 2F5/2 was measured to be 1.10 ms. Additionally, gain cross-sections were calculated for different β values. In the continuous laser experiment, the crystal demonstrated a laser output of 20.15 W at 1057 nm, with a slope efficiency of 53.3%. These experimental findings indicate that the lattice of Y3+ in the crystal is partially replaced by Lu3+ and Gd3+, resulting in a broader spectrum. Consequently, this crystal shows promising potential as a gain medium for ultrashort pulse laser crystals.

Solid State Synthesis and Characterization of Yb3+/Ho3+ Doped GdPO4 Nanophosphor for Luminescence Properties

A reliable solid-state method for synthesizing GdPO4:Yb3+/Ho3+ nanophosphor is presented, exhibiting both up and down conversion luminescent properties. The peaks were observed at 460, 550, 640, and 750 nm after excitation at 300 nm, which is followed by nonradiative resonance energy transfer (ET) with the P-O charge transfer band of Ho3+ ions. A significant up-conversion nanophosphors by enhancing Ho3+ ion emissions is accomplished. The Ho3+ ion peaks at 542 and 635 nm were identified using a strong 980 nm laser source, leading to well-crystalline nanoparticles. The present results demonstrated an enormous potential of GdPO4:Yb3+/Ho3+ for high-quality, widespread luminescence. Due to their significant quantum yield when excited at a wavelength of 300 nm, these materials exhibit a diverse array of potential applications and hold considerable potential for advancement across several industries.

Synthesis and characterization of Yb3+ activated Lu2O3 nanoparticles doped optical fiber preform for high power laser application

Yb3+-activated Lu2O3 is known to exhibit excellent thermal conductance, which can be a potential candidate to develop high-power laser fiber. Here we report the synthesis of Yb3+-activated Lu2O3 nanoparticles following the homogeneous coprecipitation method along with their material and optical characterization. Five different samples were synthesized using different concentrations of Cetyl Trimethyl Ammonium Bromide (CTAB) as a cationic surfactant, Yb–Lu ratio in the presence/absence of aluminium (Al) as an additional dopant, followed by calcination at different temperatures. Differential thermal analysis (DTA) and thermogravimetry (TG) analysis were performed to optimize the thermal annealing condition while the X-ray diffraction (XRD) analysis shows the formation of a pure bixbyite structure with an average particle size of ∼ 15 nm at 800°C that reaches up to ∼ 120 nm with increasing calcination temperature to 1400°C. The field emission scanning electron microscope (FESEM) analysis shows nearly cubic morphology while high-resolution Transmission Electron Microscope (HRTEM) analysis confirms the crystalline nature and the average particle size corroborates with the XRD analysis result. The developed nanoparticle was found to exhibit characteristics of Yb-absorption and emission peaks showing no interference with Lu2O3. The emission intensity and fluorescence lifetime of the Yb3+-activated Lu2O3 nanoparticles were found to depend on the Yb concentration, average particle size, and presence of aluminium as a co-dopant. To evaluate the practical application of the developed nanoparticles, an optical preform is developed using synthesized nanoparticles as Yb-source through modified chemical vapor deposition (MCVD) coupled with solution doping (SD) technique and the initial performance of the preform is also reported.

Design and Characterization of Yb/$$p-$$ SiO2/(Yb, In) Thin-film Transistors for 5G Resonators

Design and Characterization of Yb/$$p-$$ SiO2/(Yb, In) Thin-film Transistors for 5G Resonators

Synthesis and Characterization of Yb−Ag@TiO2 Hollow Spheres for Enhancing Visible‐Light Photocatalytic Activity

AbstractUsing melamine‐formaldehyde microspheres as templates and n‐butyl titanate, silver nitrate and ytterbium nitrate hexahydrate as raw materials, the TiO2 hollow spheres (TiO2HS), which were doped with Yb and loaded with Ag, were successfully prepared by sol‐gel template method and high‐temperature calcinations and reduction. The combined action of Yb and Ag on the photocatalytic effect of methyl orange in visible light was studied. The results show that Yb3+ did not affect the reduction of Ag+ in the synthetic process, and Ag did not affect the substitution of Yb3+ for Ti4+ into the lattice of anatase phase TiO2. The introduction of Yb created impurity energy levels in the TiO2 band gap, which broadened the light absorption range and shortened the band gap width. At the same time, the Ag with strong electron conduction ability improved the carrier transfer speed. Benefitting from the combined action of Yb and Ag, the photo‐degradation efficiency of Yb−Ag@TiO2HS on methyl orange in visible light was significantly improved compared with that of undoped, Yb‐doped and Ag‐loaded TiO2HS. The degradation efficiency of Yb−Ag@TiO2HS on methyl orange was 7 times, 3 times and 4 times higher than that of TiO2HS, Yb@TiO2HS and Ag@TiO2HS, respectively.

Modifying LnHPDO3A Chelates for Improved T1 and CEST MRI Applications

The new ligand HPDO3MA [(R,R,R,R)-10-(2-hydroxypropyl)-α,α',α''-trimethyl-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid] was designed to combine and optimize the chemical properties of the macrocyclic ligands HPDO3A and DOTMA. The presence of the methyl groups on the acetic pendant arms of HPDO3A is expected to rigidify the structure of the ligand and favor an increase of the kinetic inertness of the Ln complexes. 1 H NMR spectra of Eu(HPDO3MA) displayed the presence of two pairs of diastereoisomers: SAP (square antiprismatic) and TSAP (twisted square antiprismatic) isomers (56 and 44 %, respectively). In addition, 1 H and 17 O relaxometric NMR studies of Gd(HPDO3MA) showed approximately a 10 % increase in relaxivity and a faster water exchange rate with respect to Gd(HPDO3A). Moreover, a detailed chemical exchange saturation transfer (CEST) characterization of Yb(HPDO3MA) displayed a sensitivity about two times larger than that of Yb(HPDO3A) both in phantom and in cell labeling experiments. Finally, the kinetic inertness of Yb(HPDO3MA) was measured to be twice as high as that of Yb(HPDO3A), with a dissociation half-life at physiological pH of about 2500 years.

Growth and characterization of Yb:Ho:YAG single crystal fiber

High quality Yb and Ho co-doped Y3Al5O12 single crystal fibers have been successfully grown by the laser heated pedestal growth method of up to 124 mm in length and 450 μm in diameter for the first time. The results of inductively coupled plasma-atomic emission spectrometry analysis, X-ray diffraction and Raman spectroscopy reveal that the lattice structure and doping concentrations of the SCF are the same as that of the bulk. Scanning electron microscopy microphotographs shows that the fibers only have minor diameter fluctuations within 0.5%.

Evaluation of TeO2 content on the optical and spectroscopic properties of Yb3 +-doped calcium borotellurite glasses

This paper reports the synthesis and the characterization of Yb3+-doped calcium borotellurite (CaBTeX) glasses with composition 10CaF2–(29.5−0.4x)CaO–(60−0.6x)B2O3–xTeO2–0.5Yb2O3 (x=10, 16, 22, 31 and 54mol%). The results of XRD confirm the amorphous character of all the samples. The density, molar volume, refractive index and electronic polarizability values show an increase with TeO2 content. Otherwise, the optical band gap energy shows a decrease with the increase of TeO2 content. The replacement of CaO and B2O3 by TeO2 changes the glass structure, which decreases the excited Yb3+/cm3 and, consequently, the luminescence intensity. The temperature dependence of luminescence was studied for all the samples up to 420K. The fluorescence lifetime does not change significantly due to TeO2 addition. In addition, absorption and emission cross section were calculated and present high values as compared to other tellurite and phosphate glasses.

Wet‐Route Synthesis and Characterization of Yb:CaF2 Optical Ceramics

This paper reports a new strainless fabrication method for ytterbium‐doped CaF2 laser ceramics involving no drying step before green body casting. The nanoparticles were kept in aqueous solution until green body shaping. Centrifugation was used to obtain correct compactness of the green body before sintering. Characterizations were conducted at different steps of the fabrication process. No grain boundaries oxidation was observed in the sintered ceramics although the nanoparticles were permanently maintained in water until they were sintered. Finally, these ceramics are more homogeneous and have less light scattering defects (no porosity), and present improved optical properties when compared to ceramics obtained from dried nanopowders.

Spectroscopic and lasing characteristics of Yb:YGAG ceramic at cryogenic temperatures

We present the spectroscopic characterization and continuous-wave laser operation of a new Yb doped Y3Ga2A13O12 (Yb:YGAG) ceramic material at cryogenic temperatures. The peak absorption is centered at 942 nm, zero phonon line at 970 nm and the peak emission at 1028 nm. The emission bandwidth is as much as three times larger than Yb:YAG at cryogenic temperatures which makes this material very promising for sub-picosecond pulse generation. At cryogenic continuous-wave laser operation, a maximum output of 2.92W with a slope efficiency of 20.3% at 60K is achieved.

Evaluation of growth, thermal and spectroscopic properties of Yb^3+-doped GSGG crystals for use in ultrashort pulsed and tunable lasers

A series of high quality Yb3+-doped gadolinium scandium gallium garnet (Yb:GSGG) single crystals with different Yb3+ ion concentration (7.5, 10, 15 and 30 at.%) has been grown by means of optical floating zone (OFZ). Crystal structure was analyzed with X-ray powder diffraction (XRPD), showing that the Yb:GSGG crystal possesses a cubic structure with space group Ia3d, and the lattice constants decrease linearly as the Yb3+ concentration increases. Effective elemental segregation coefficients and chemical composition were investigated by X-ray fluorescence (XRF), suggesting that some Yb3+ ions occupy the octahedral site when the Yb3+ ion concentration is higher than 10 at.%. The thermal properties of Yb:GSGG crystals were systematically studied by measuring the specific heat, thermal expansion and thermal diffusion coefficients. Thermal conductivity was then calculated, and it exhibits a tendency to decrease with increasing Yb3+ ion concentration. Spectroscopic characterization of Yb:GSGG crystals was performed at room temperature (RT), and the stimulated emission cross section was calculated using the reciprocity method (RM) and the Fuchtbauer−Ladenburg (F−L) formula, respectively. In comparison with the radiative lifetime of the 2F5/2→2F7/2 transition, the effect of radiation trapping on the fluorescence lifetime is discussed. These research results indicate that Yb:GSGG can be regarded as a promising candidate for use in an ultrashort pulsed and tunable laser.

Preparation and Characterization of Yb<SUP>3</SUP><SUP>+</SUP>-Doped Metaphosphate Glasses for High Energy and High Power Laser Applications

Preparation and Characterization of Yb<SUP>3</SUP><SUP>+</SUP>-Doped Metaphosphate Glasses for High Energy and High Power Laser Applications

Theoretical analysis of Yb3+-doped double-clad fiber lasers using a new analytical method

The approximate analytical solutions to the threshold pump power and output laser power of Yb3+-doped double-clad fiber lasers have been deduced based on the rate equations with the scattering losses of pump and laser signal. In the rate equations, the relation between the attenuation of the pump light and the population density on the upper level is considered. The characteristics of Yb3+-doped double-clad fiber lasers have been investigated.

Synthesis and characterization of Yb and Er based monosilicate powders and durability of plasma sprayed Yb2SiO5 coatings on C/C–SiC composites

Rare-earth silicates such as Yb2SiO5 and Er2SiO5 are promising environmental barrier coating materials for ceramic matrix composites. In this work, Yb2SiO5 and Er2SiO5 ceramic powders have been synthesized by solid-state reaction using Yb2O3, Er2O3 and SiO2 as starting materials. The fabricated powders were subjected to spray drying treatment for subsequent synthesis of coatings by plasma spraying. The spray drying resulted in well-dispersed and spherical powder particles with good flowability. Analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry and differential scanning calorimetry (TGA/DSC) and dilatometry were applied to study the microstructural and thermal characteristics of the powders. Ultra-high purity monosilicate powders formed as a result of heating treatments at 1400 degrees C in a box furnace for 20h. TG/DSC revealed the genesis temperatures of the silicate formation (low temperature polymorphs) and also showed that the solid-state reactions to form Yb and Er based monosilicates proceeded without any weight-loss in the tested temperature range. The values of coefficients of thermal expansion (CTE) of the fabricated compounds are found to be 7.1 ppm/degrees C for Yb2SiO5 and 7.5 ppm/degrees C for Er2SiO5 by dilatometric measurements. Besides these studies, coating formation by plasma spraying of spray-dried Yb2SiO5 powders on the ceramic matrix composite specimen such as C/C-SiC has also been evaluated. Well-adhered and uniformed coatings result on composite specimens whose durability is tested by thermal cycling from similar to 400 degrees C to 1500 degrees C in a gas burner rig. (C) 2011 Elsevier B.V. All rights reserved.

Fabrication and characterization of Yb^3+-doped gain-guided index-antiguided fiber with D-shaped inner cladding

Yb3+doped gain-guided index-antiguided fibers based on phosphate glasses are drawn using the rod-in-tube technique. These fibers have a circular core with 200 μm diameter and a D-shaped inner cladding with a 630/480 μm diameter for the longer/shorter axis. The negative index profile is present in these fibers, in which the core index of refraction is 0.019% lower than that of the inner cladding. Moreover, their laser amplifier characteristics are experimentally demonstrated, and the method of further improvement in laser performance is suggested.

Synthesis and characterization of Yb 3+,Tm 3+:Ba 2YF 7 nanocrystalline with efficient upconversion fluorescence

A novel upconversion luminescence nanocrystals Yb 3+,Tm 3+:Ba 2YF 7 were synthesized via the hydrothermal method. They have uniform morphology with a mean size of 30 nm even if annealed at 600 °C. Pumped by 980 nm laser diode the as-synthesized powers emit ultraviolet/blue light, which is in the range of the specific upconversion luminescent spectra of Tm 3+ ions. After post-annealing at 600 °C in an argon atmosphere for 2 h, their upconversion luminescence intensity is 5 multiple improved and the ultraviolet/blue light can even be seen by the naked eyes under a low excitation power of 20 mW. This indicates that Ba 2YF 7 is a very effective luminescent host material. Excitation power dependences of individual upconversion emission intensity are plotted, which partly uncover the upconversion luminescence mechanism of Tm 3+ ions.

Investigations of Yb-doped optical fiber using selective laser excitation

The method of tunable site-selective laser excitation was used for a study of the spectral and fluorescence characteristics of Yb3+ optical centers in laser optical fiber. Decay curves and positions of fluorescence spectra maxima at different wavelengths of selective laser excitation and positions of excitation spectra maxima at different fluorescence selective registration provide new information on lifetimes and Stark energy distribution among inhomogeneously broadened Yb3+ lines. The obtained Stark splitting energy distribution diagram demonstrates the tuneability of Yb3+ laser oscillation wavelength under tunable excitation of a pump laser.

Investigation on the fabrication and luminescence characteristics of Yb3+ and Al3+ Co-doped silicate glasses

We demonstrate a new method for fabrication of rare-doped silica-based glass, which is liquid doped with non-chemical vapor deposition (non-CVD) melting process. The Ytterbium doped silica-based glass with the ratio of 98SiO2-0.5Yb2O3-1.5Al2O3wt% is achieved by using this method. The refractive index (nD) and the density(ρ) of the glass are 1.519 and 2.62g/cm3 respectively. In measurement experiment, it shows that it has strong absorption in the wavelength range from 850nm to 1050nm, and the main absorption peak is at 978nm and the secondary absorption peak is at 919nm. Using the laser with wavelength of 978nm as pumping source, the emission peak is at 1018nm in the fluorescence spectrum with a 71.8nm fluorescence half-line width. Meanwhile, the integrated absorption cross section, stimulated emission cross section, fluorescence time, saturated pump intensity, minimum pump intensity and other parameters are calculated. Test results indicate that the doped silica-based glass has good thermal stability and large power threshold, which is an ideal gain medium for large power photonic crystal fiber lasers.

Ytterbium-Doped Yettrium Aluminum Garnet Crystal Fiber Multipass Ring Laser

We report the growth of ytterbium-doped yettrium aluminum garnet (Yb:YAG) crystal fibers by the laser-heated pedestal growth (LHPG) method. The characteristics of Yb:YAG crystal fibers were analyzed by electron probe microanalyzer (EPMA) and X-ray diffraction measurements. The small crystal fiber diameter makes it effective for heat removal from a high-Yb3+-concentration and quasi-three-level gain medium. The length of this crystal-fiber-based high absorption can be shorter, which is eminently suitable for a multipass ring cavity to maintain cavity stability and mode symmetry. We successfully demonstrated a two-mirror multipass ring laser with 54.7% slope efficiency, which is higher than the 50.3% for a bulk Yb:YAG laser.

Characterization of Yb:YAG ceramics as laser media

We report the preparation and characterization of 9.8 at.% Yb 3+ doped YAG polycrystalline ceramics for laser applications. Reactive sintering of commercial powders in a clean atmosphere and under high vacuum has been used to achieve the YAG phase. The selected experimental conditions for the powder treatment, shaping and sintering are described and their influence on the optical quality of the obtained samples has been discussed. Microstructural, optical and laser characterization of the ceramics have been performed. In particular the influence of the pre-sintering (calcination) and sintering cycles has been investigated by laser characterization allowing to find unexpected loss mechanisms that cannot be revealed by standard optical characterization.