Nm In Er Research Articles

Intense orange emission in Pr3+ and NIR emission at 1.53 μm in Er3+ doped zinc phosphate glasses for potential broadband optical amplifier

Praseodymium (Pr3+) and Erbium (Er3+) doped zinc phosphate glasses with chemical compositions (60 − x) NH4H2PO4 + 20ZnO + 10BaF2 + 10NaF + xRE (where RE = Pr6O11 and Er2O3, x = 0.1, 0.5, 1.0, 1.5 and 2.0 mol%) have been prepared by melt quenching technique. Amorphous structure was ascertained by XRD analysis. The functional and vibrational bands have been assigned and clearly elucidated by FT-IR and Raman spectral profiles for all the glass samples. Judd–Ofelt (J–O) intensity parameters (Ω λ : λ = 2, 4, 6) have been obtained from the spectral intensities of different absorption bands of Pr3+ and Er3+ ions through optical absorption spectra. The radiative properties such as radiative transition probabilities (A R ), radiative lifetimes (τ R ) and branching ratios (β R ) for different excited states were calculated by using J–O intensity parameters. Visible photoluminescence spectra have exhibited six emission bands (3P1 → 3H5, 1D2 → 3H4, 3P0 → 3F2, 3P1 → 3F3, 3P0 → 3F3 and 3P0 → 3F4 states) for all the concentrations of Pr3+ ions. NIR photoluminescence spectra exhibited one emission band (4I15/2 → 4I13/2) of Er3+ ions. The energy transfer mechanism that leads to the quenching of lifetimes of 1D2 and 4I13/2 states have been discussed at higher concentrations of Pr3+ and Er3+ ions, respectively. These glasses were suggested as suitable hosts to produce intense orange emission at 608 nm for Pr3+ ion and efficient lasing action in NIR region at 1534 nm for Er3+ ion.

Synthesis, structural, X-ray photoelectron spectroscopy (XPS) studies and IR induced anisotropy of Tl4HgI6 single crystals

In the present work, we report on the synthesis and structural properties including X-ray protoelectron spectroscopy (XPS) analysis of Tl4HgI6 crystals that were grown by Bridgman-Stockbarger method up to 80 mm in length and 18 mm in diameter. The existence of the ternary compound Tl4HgI6 that melts incongruently at 641 K was confirmed. Phase equilibria and structural properties for the TlI–HgI2 system were investigated by differential thermal analysis (DTA) and X-ray diffraction (XRD) methods. X-ray photoelectron spectra were measured for both pristine and Ar+ ion-bombarded Tl4HgI6 single crystal surfaces. The data reveal that the Tl4HgI6 single crystal is sensitive with respect to Ar+ ion-bombardment as 3.0 keV Ar+ irradiation over 5 min at an ion current density 14 μA/cm2 induces changes to the elemental stoichiometry of the Tl4HgI6 surface, leading to a decrease of the mercury content in the topmost surface layers. X-ray photoelectron spectroscopy (XPS) measurements indicate very low hygroscopic nature of the Tl4HgI6 single crystal surface. The IR coherent bicolor laser treatment at wavelengths 10.6/5.3 μm has shown an occurrence of anisotropy at wavelengths 1540 nm of Er:glass laser. This may open the applications of Tl4HgI6 as a material for IR laser triggering.

Er^3+ doped and Er^3+/Pr^3+ co-doped gallium-antimony-sulphur chalcogenide glasses for infrared applications

Er3+- and Pr3+-doped Ga-Sb-S chalcogenide glasses were prepared by the traditional melt-quenching method, and their optical properties in the infrared range were investigated. In order to enhance the mid infrared emissions at 2740 nm of Er3+, Pr3+ was introduced into the glass system. Under 808 nm excitation, the emission of 2740 nm was significantly enhanced in the co-doped sample while the emission of 1550 nm was oppositely reduced. Fluorescence decay results indicated that the lifetime of Er3+: 4I13/2 at 1550 nm was evidently decreased in the co-doped sample. The mechanism of the energy transfer process between Er3+ and Pr3+ ions were investigated in this work.

Site-selective measurement of relaxation properties at 980 nm in Er $$^{3+}$$ 3 + -doped congruent and stoichiometric lithium niobate crystals

A pump-probe-type saturation spectroscopic experiment has been performed at 980 nm to measure the homogeneous linewidth of the $$^4$$ I $$_{11/2}$$ – $$^4$$ I $$_{15/2}$$ transition and the lifetime of the $$^4$$ I $$_{11/2}$$ state of erbium embedded into lithium niobate single crystals. There are several non-equivalent Er $$^{3+}_{\mathrm{Li}^+}$$ –V $$_{\mathrm{Li}^+}$$ sites with differently oriented defect structure for charge compensation. These non-equivalent centers differ in their transition energies. Hence, our measurements have been done at two nearby frequencies, addressing groups of erbium ions located at non-equivalent sites. The results are compared with lifetime calculations and measurements found in the literature and with the predictions of our simple model calculation.

Graphene oxide paper as a saturable absorber for Er- and Tm-doped fiber lasers

In this work pulse generation in both the 1.5 and 2 μm spectral ranges using a graphene oxide (GO)-paper-based saturable absorber in Er- and Tm-doped fiber lasers is presented. The article describes the fabrication method of GO paper and its characterization. The performance of both lasers is discussed in detail. Stable, mode-locked operation provides 613 fs and 1.36 ps soliton pulses centered at 1565.9 and 1961.6 nm in Er- and Tm-doped fiber lasers, respectively. Furthermore, scaling of spectral width, and hence the pulse duration, by increasing the number of GO paper layers in the Er-doped laser is described. The versatility and simplicity of GO paper fabrication combined with the possibility of scaling the optical spectrum full width at half-maximum are essential features that make it a good candidate for ultrafast low-power mode-locked lasers operating in different spectral regions.

264 W output power at 1585 nm in Er-Yb codoped fiber laser using in-band pumping.

We demonstrate a high-power cladding-pumped Er-Yb codoped fiber laser with 74% efficiency. A pump-limited output power of 264 W is obtained using in-band pumping at 1535 nm. We compare the efficiency of 1480 and 1535 nm pumping through numerical simulations and experimental measurements.

Phase-Modified Up-Conversion Luminescence in Er-Doped Single-Crystal PbTiO3 Nanofibers

The Er-doped preperovskite and perovskite single-crystal PbTiO3 (PTO) nanofibers with a series of doping concentration (0–4 mol %) were successfully synthesized by hydrothermal method and solid state phase transformation method, respectively. The XRD, XPS, and Raman results indicated that Er3+ occupied Pb2+ site in preperovskite PTO and Ti4+ site in perovskite PTO nanofibers. The photoluminescence (PL) measurements indicated that only the strong green emission corresponding to the preperovskite PTO host matrix was observed, whereas up-conversion (UC) emission under infrared excitation (980 nm) was absent. In contrast, the strong green emission (at 524 and 554 nm) and the weak red emission around 670 nm of Er3+ occurred in the PL and UC PL processes of Er-doped perovskite PTO nanofibers. The distinguished difference in these two kinds of nanofibers might be attributed to the substitution sites and chemical environments of Er3+. It is suggested that such Er-doped single-crystal perovskite PTO nanofibers cou...

Phonon-modulated upconversion luminescence properties in some Er3+ and Yb3+ co-activated oxides

The competition between 4I13/2–4I15/2 near-infrared downconversion emissions and visible upconversion emissions of 2H11/2/4S3/2/4F9/2–4I15/2 is a vital factor for obtaining efficient upconversion luminescence (UCL) in Er3+ and Yb3+ co-activated oxides. In this paper, we systemically studied the entire emission spectra of Er3+ ranging from 400–1700 nm in Er3+ and Yb3+ co-activated cubic Y2O3, tetragonal GdVO4 and tetragonal NaGd(WO4)2 micro-sized powders, prepared by the same sol–gel method, which have different phonon thresholds, 600 cm−1, 880 cm−1 and 1000 cm−1, respectively. It is interesting to observe that in these phosphors, the visible UCL of Er3+ relative to near-infrared emissions increase remarkably with the increase of phonon thresholds. In comparison with the UCL in the Y2O3 host, the UCL in YVO4 and tetragonal NaGd(WO4)2 was tremendously improved by 9.5- and 120-fold, respectively. The UCL intensity of the NaGd(WO4)2:Yb3+/Er3+ was comparable to that of the famous UCP NaYF4:Yb3+/Er3+. A model was proposed to explain the phonon-modulated UC process. This work is of great significance in the search for a novel, efficient UCP.

Peculiarities of component interaction in {Gd, Er}–V–Sn Ternary systems at 870 K and crystal structure of RV 6Sn 6 stannides

The phase equilibria in the Gd–V–Sn and Er–V–Sn ternary systems were studied at 870 K by means of X-ray and metallographic analyses in the whole concentration range. Both Gd–V–Sn and Er–V–Sn systems are characterized by formation of one ternary compound at investigated temperature, with stoichiometry RV 6Sn 6 (SmMn 6Sn 6-type, space group P6/ mmm, a = 0.55322(3) nm, c = 0.91949(7) nm for Gd, a = 0.55191(2) nm, c = 0.91869(8) nm for Er). Solubility of the third component in the binary compounds was not observed. Compounds with the SmMn 6Sn 6-type were also found with Dy, Ho, Tm, and Lu, while YV 6Sn 6 compound crystallizes in HfFe 6Ge 6 structure type. All investigated compounds are the first ternary stannides with rare earth elements and vanadium.

Temperature sensitive near‐infrared luminescence of Er3+ ions in LiYF4

AbstractThe photoluminescence spectra at 800‐1650 nm of Er3+ ions doped in LiYF4 crystal are investigated at temperatures between 296 and 12 K. Intense emissions were observed at 1460‐1540, 1205‐1235, 960‐1020, and 830‐860 nm. As temperature is increased from 12 K to room temperature, broadening and intensity increase were observed for the emissions at 1460‐1540 and 960‐1020 nm, but not observed for emissions at 1205‐1235 and 830‐860 nm. The broadening is explained by the transitions from upper Stark levels which are thermally excited at higher temperatures. Level assignment has been made for all the emissions including several weak emissions (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Silver/silicon nanostructure for surface-enhanced fluorescence of Ln3+ (LnNd, Ho, and Er)

The surface-enhanced fluorescence of lanthanide ions (neodymium ions Nd3+, holmium ions Ho3+, and erbium ions Er3+) owing to resonant plasmons oscillation on the surface of Ag/Si nanostructure was described. In the presence of Ag/Si nanomaterials, the fluorescence peaks were significantly enhanced, which resulted in a typical 185-fold enhancement at 592 nm for Nd3+, 82-fold at 550 nm for Ho3+, and 80-fold at 533 nm for Er3+ at the concentration of 0.05 M. This Ag/Si nanostructure had larger enhancement factor than that caused by unsupported Ag nanoparticles, which might be attributed to the local field overlap originated from the closed and fixed Ag nanoparticles on silicon nanowires.

Preparation and photoluminescence properties of RE:Na 3La 9O 3(BO 3) 8 ( RE=Er, Yb) crystals

Using Na 2CO 3–H 3BO 3–NaF as fluxes, transparent RE:Na 3La 9O 3(BO 3) 8 (abbr. RE:NLBO, RE=Er, Yb) crystals have been grown by the top seed solution growth (TSSG) method. The X-ray powder diffraction analysis shows that the RE:NLBO crystals have the same structure with NLBO. The element contents were determined by molar to be 0.64% Er 3+ in Er:NLBO, 2.70% Yb 3+ in Yb:NLBO, respectively. The polarized absorption spectra of RE:NLBO have been measured at room temperature and show that both Er:NLBO and Yb:NLBO have a strong absorption bands near 980 nm with wide FWHM (Full Wave at Half Maximum) (21 nm for Er:NLBO and 25 nm for Yb:NLBO). Fluorescence spectra have been recorded. Yb:NLBO has the emission peaks at 985 nm, 1028 nm and 1079 nm and the emission peak of Er:NLBO is at 1536 nm. Spectral parameters have been calculated by the Judd–Ofelt theory for Er:NLBO and the reciprocity method for Yb:NLBO, respectively. The calculated values show that Er:NLBO is a candidate of 1.55 μm laser crystals and Yb:NLBO is a candidate for self-frequency doubling crystal.

Processing and characterization of new passive and active oxysulfide glasses in the Ge–Ga–Sb–S–O system

New passive and active oxysulfide glasses have been prepared in the Ge–Ga–Sb–S–O system employing a two-step melting process which involves the processing of the chalcogenide glass (ChG) and its subsequent melting with amorphous GeO 2 or Sb 2O 3 powder. Optical characterization of the oxysulfide glasses has shown that the UV cut-off wavelength decreases with increasing oxygen content. Using Raman spectroscopy, correlations have been made between the formation of new Ge- and Sb-based oxysulfide structural units, the Sb content and the O/S ratio. We demonstrate the successful processing of active rare earth doped oxysulfide glasses by melting the chalcogenide glass with Er 2O 3 and Sb 2O 3 and also by melting the Er 3+ doped chalcogenide glass with Sb 2O 3. Modification of the emission spectra at 1500 nm of Er 3+ doped samples with the introduction of oxygen revealed that Er 3+ most likely exists in dual O- and S-neighbor environments. Finally, the photo-response of these new glasses upon near-IR femtosecond laser irradiation has been investigated as a function of Sb content and O/S ratio and shows that the glasses are photo-sensitive to NIR fs laser light with the magnitude of the photo-sensitivity dependent on the glass’ Sb content and O/S ratio.

Optical properties of PMMA doped with erbium(III) and ytterbium(III) complexes

AbstractIn this article, we report the fabrication and optical/spectroscopic properties of polymethylmethacrylate (PMMA) doped with rare earth (RE) (Er3+ and Er3+/Yb3+) ions. Infrared spectroscopy revealed only very weak OH stretching vibration peaks in the samples, which is important if satisfactory photoluminescence is to be observed at 1530 nm. Measurement of transmission spectra in the wavelength ranges from 300 to 700 nm for Er3+‐doped samples and from 900 to 1050 nm for Yb3+‐doped samples enabled us to observe the 4G11/2 (377 nm) and 2H11/2 (519 nm) transmission bands typical for Er3+‐doped samples, as well as the 2F5/2 (975 nm) band typical for Yb3+‐doped samples. Under excitation at 980 nm, at room temperature, the characteristic Er3+ emission at 1530 nm was also observed with improving trend when the higher RE concentrations were applied. The results indicate that the PMMA reveals very low tendency to the RE clustering, which together with low cost and easy fabrication make it a material with a great potential in the active photonics devices. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers

Facile synthesis, structural and optical characterization of LnF 3:Re nanocrystals by ionic liquid-based hydrothermal process

A novel and easy synthesis of highly luminescent rare-earth ion-doped LnF 3 (LnF 3:Re) nanocrystals by ionic liquid-based hydrothermal process was reported. Ionic liquids [bmim]BF 4 (1-butyl, 2-methylimidazolium tetrafluoroborate) acts as co-solvent, template and reactant. X-ray diffraction and field emission scanning electron microscopy were used to characterize the structural properties of the products. The luminescent properties of LaF 3:Re nanocrystals were evaluated under ultraviolet (397 nm for Eu 3+, 254 nm for Ce 3+, Tb 3+) and (or) near-infrared (980 nm for Er 3+) excitation. Under 980 nm laser excitation, intense green upconversion emissions were observed for LaF 3:Er(1%) samples in the solid state and dispersion in water and ethanol. The quantum efficiency of LaF 3:Ce(15%),Tb(5%) nanocrystals was about 34%. Our reports provide a facile method for the preparation of LnF 3:Re nanocrystals with excellent photoluminescent properties.

Optical properties of Er 3+ in MoO 3–Bi 2O 3–TeO 2 glasses

Erbium-doped MoO 3−Bi 2O 3−TeO 2 (MBT) glasses suitable for broadband optical amplifier applications have been fabricated and characterized optically. The maximum phonon band of undoped glasses is at 915 cm −1, and the emission from the Er 3+: 4 I 13/2 → 4 I 15/2 transition locates around 1.53 μm with a full width at half maximum (FWHM) of ∼80 nm. The lifetime and quantum efficiency of the 4 I 13/2 level are 2.13 ms and ∼90%, respectively. Under the same measurement condition, the upconversion emission intensities at 550 nm in Er 3+-doped MBT glasses is about 30 times weaker than that in Er 3+-doped Na 2O−ZnO−TeO 2 (NZT) glasses.

Controllable propagation of light pulses in Er-doped fibers with saturable absorption

We report controllable (slow or fast) propagation of low-intensity probe-light pulses through erbium-doped fiber periodically saturated by the synchronized master-pulse sequence. These two pulse sequences could have significantly different carrier wavelengths within the fundamental absorption spectrum 1470-1570 nm of Er(+3) ions. The effect of fractional delay or advancement grew with the fiber optical absorption at the probe wavelength and could be significantly stronger than that at the saturating wavelength. The probe-pulse advancement was observed in the case when the saturating and probe waves were modulated approximately in antiphase. The observed effects are explained in the framework of a simple model of a periodically saturated homogeneously broadened absorption line.

Er$^{3+}$–Y$^{3+}$-Codoped Al$_{2}$O$_{3}$ for High-Temperature Sensing

Optical high-temperature sensing using the fluorescence intensity ratio (FIR) technique of green up-conversion emissions at 523 and 546 nm in Er <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> -Y <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> -codoped Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> was studied in a wide temperature range of 295 K-973 K. The maximum sensitivity and the temperature resolution derived from the FIR technique are approximately 0.0035 K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> and 0.3 K, respectively, which indicated that Er <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> -Y <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> -codoped Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> plays an important role for applications in the optical high-temperature sensing.

Thermal stability and spectroscopic properties of Er 3+-doped antimony-borosilicate glasses

This paper reports on the optical spectroscopic properties and thermal stability of Er 3+-doped antimony-borosilicate glasses for developing 1.5 μm optical amplifiers. Upon excitation at 980 nm laser diode, an intense 1.5 μm infrared fluorescence has been observed with the maximum full width at half maximum (FWHM) of 90 nm for Er 3+-doped antimony-borosilicate glasses. The emission cross-section and the lifetime of the 4 I 13/2 level of Er 3+ ions are 6.3 × 10 −21 cm 2 and 0.30 ms, respectively. It is noted that the product of the emission cross-section and FWHM of the glass studied is as great as 567 × 10 −21 cm 2 nm, which is comparable or higher than that of bismuthate and tellurite glasses.

Growth and spectral properties of Er 3+/Yb 3+-co-doped Ca 3Ln 2(BO 3) 4 (Ln=Gd, La) crystals

This paper reports the investigation of the growth and spectroscopic properties of Er 3+/Yb 3+-co-doped Ca 3Gd 2(BO 3) 4 and Ca 3La 2(BO 3) 4 crystals. Both crystals have been grown by the Czochralski method. The specific heats are 0.37 J/g/K and 0.45 J/g/K at 350 K for Er 3+/Yb 3+:Ca 3Gd 2(BO 3) 4 and Er 3+/Yb 3+:Ca 3La 2(BO 3) 4, respectively. They have a large absorption coefficient and broad full-width at half-maximum, which are 22 cm −1 and 7 nm for Er 3+/Yb 3+:Ca 3Gd 2(BO 3) 4 and 14.5 cm −1 and 9 nm for Er 3+/Yb 3+:Ca 3La 2(BO 3) 4, respectively. A strong emission band at 1450–1650 nm due to the 4I 13/2→ 4I 15/2 transitions in Er 3+ was observed. The fluorescence lifetimes are about 590 and 650 μs for Er 3+/Yb 3+:Ca 3Gd 2(BO 3) 4 and Er 3+/Yb 3+:Ca 3La 2(BO 3) 4 crystals, respectively. The results show that when Yb 3+ and Er 3+ ions were co-doped into Ca 3Gd 2(BO 3) 4 and Ca 3La 2(BO 3) 4 crystals, Yb 3+ as the sensitizer can enhance the absorption efficiency and lower the laser oscillations threshold of 1.5 μm Er 3+ laser.