Spectroscopic Properties Of Er3 Research Articles

Spectroscopic properties of Er3+-doped fluoroindate glasses

The optical and thermal properties of a new class of fluoroindate glass with different erbium contents were investigated via Raman, transmission, and fluorescence spectroscopies, fluorescence decay curve analysis, and differential scanning calorimetry. The strength parameters of the samples were calculated using the Judd–Ofelt theory. The mid-infrared luminescence properties of erbium-doped fluoroindate glasses were studied, and a strong emission at 2.7 μm was obtained. Compared with the traditional ZBLAN glass, this glass has excellent emission properties, especially a longer fluorescence lifetime (7.09 ms) and larger emission cross-section (6.95 × 10−21 cm2) at 2.7 μm. The results indicate that fluoroindate glass is an attractive host for mid-infrared lasers and as a gain medium for optical amplifier applications.

Influence of Al/Er ratio on the optical properties and structures of Er3+/ Al3+ co-doped silica glasses

In this study, Er3+/Al3+ co-doped silica glasses with various Al/Er ratios ranging from 0 to 200 and a constant Er2O3 amount were prepared using the sol-gel method combined with high-temperature vacuum sintering. The absorption, emission spectra, and fluorescence lifetime of Er3+ ions were recorded and the absorption and emission cross sections were calculated. Using Raman, 27Al and 29Si magic angle spinning nuclear magnetic resonance (MAS-NMR), 27Al triple-quantum (TQ)-MAS-NMR, and electron paramagnetic resonance (EPR) spectroscopies, the physical and optical properties were correlated with the glass structural modifications due to the Al/Er ratio change. With the increase in the Al/Er ratio, the content of Al3+ ions around the Er3+ ions gradually increased. Meanwhile, the AlO5 and AlO6 polyhedrons increased at the expense of the AlO4 and SiO4 tetrahedrons, which resulted in an improved symmetry and better ionic Er–O bonds. These structural changes led to the site-to-site variations in the Er3+ local environment and the changes in the ligand field strength of the Er–O bonds. This, in turn, resulted in the inhomogeneous broadening of the absorption and emission spectra, with a blue shift of both absorption and emission peaks and a decrease in both absorption and emission at 1.53 μm. With the increase in Al/Er ratio, the full width at half maximum (FWHM) of the emission increased from 27.2 to 54.3 nm. The FWHM × emission cross section (σemi) parameter for evaluating broadband amplification behavior was 30.1 × 10−20 cm2 · nm. This work reveals the close relationship between the glass structure and the spectroscopic properties of Er3+ ions and provides an important reference for the design of broadband amplifier materials in the field of optical communication.

Evaluation of Growth, Thermal, and Spectroscopic Properties of Er3+-Doped CLNGG Crystals for Use in 2.7 μm Laser

A series of optical-quality Er3+-doped calcium lithium niobium gallium garnet (CLNGG) single crystals with different Er3+ ion concentration (10, 15 and 30 at.%) has been grown by the Czochralski method. A comparative study of their structure, thermal, and spectroscopic properties is performed. Crystal structure was analyzed with X-ray powder diffraction (XRPD) and refined by the Rietveld method, results showing that the Er:CLNGG crystal possesses a cubic structure with space group Ia3¯d, and the lattice constants decrease linearly as the Er3+ concentration increase. The complete set of thermal properties were systematically studied for the first time. It has been found that all the thermal conductivities increase with temperature, indicating a glass-like behavior. Effect of Er3+ concentration on spectroscopic properties of Er:CLNGG crystals was studied. Results show that with the Er3+ concentration increase, the NIR fluorescence around 1600 nm weakens, while the Mid-IR fluorescence intensity around 2700 nm strengthens. Fluorescence lifetime of 4I13/2 decreased faster than that of 4I11/2 with the Er3+ concentration increase, which is beneficial for surmounting the “bottleneck” effect to achieve 2.7 μm laser. All the results show that CLNGG crystal with high Er3+ concentration is a potential candidate for the 2.7 μm laser.

Germanium concentration effects on the visible emission properties of Er3+ in tellurite glasses

The influence of different Germanium dioxide concentration on the structural, thermal, optical and spectroscopic properties of Er3+ doped tellurite glasses was carefully investigated. The glasses were prepared by melt-quenching technique. The samples were characterized by UV–visible–near-infrared spectroscopy, downshift emission spectroscopy, Raman spectroscopy, lifetime of green emission and up-conversion under near-infrared laser diode excitation at 975 nm. The Judd-Ofelt analysis was performed based on the absorption spectra of the glasses in order to obtain the Judd-Ofelt parameters (Ωλ), radiative transition rates, radiative lifetimes and quantum efficiency. The solubility of Er3+ into the host vitreous matrix, the enhancement in the luminescence intensity and improvement in the thermal stability (≥ 100 ∘C) of the glasses was verified on introducing GeO2.

Spectroscopic properties of Er:BZMT ceramics for laser emission

We report on the characterization and analysis of the spectroscopic properties of an Er3+-doped Ba(Zr,Mg,Ta)O3 (Er:BZMT) transparent ceramic showing a disordered perovskite structure. The Judd-Ofelt model was applied to estimate the radiative lifetimes and branching ratios of the 1.5 and 3 µm emission transitions, which are potential for laser operation. The experimental fluorescence lifetimes of the transitions of 4I13/2 → 4I15/2 and 4I11/2 → 4I13/2 were recorded to calculate the radiative quantum efficiencies. According to the analysis, significant non-radiative relaxation processes from the 4I11/2 multiplets should exist in the Er:BZMT system, which makes this material more suitable for laser operation at 1.6 µm. Finally, the gain cross-section for the potential 1.6 µm laser emission was calculated, showing a broad tuning range from less than 1.6 µm to around 1.7 µm. This result also indicates that femtosecond level laser pulses are possible using Er:BZMT as laser gain medium.

Thermal and spectroscopic properties of Er3+-doped fluorotellurite glasses modified with TiO2 and BaO

We have investigated the thermal and spectroscopic properties of Er3+-doped fluorotellurite glass with the basic molar composition 75%TeO2–10%P2O5–10%ZnO–5%PbF2 and the glasses modified by substituting 5%TeO2 by a metal oxide, namely TiO2 or BaO. As follows from the thermal studies, the glass containing TiO2 as a modifier exhibits a higher stability against crystallization with respect to two other glasses. The ellipsometric data have provided a Sellmeier-type dispersion relation of the refractive index of the investigated glasses. The absorption and fluorescence spectra, along with the photoluminescence decay of the 4I13/2 levels of the Er3+ ion, have been analyzed within the Judd–Ofelt and Fuchtbauer-Ladenburg approaches. It appears that the quantum efficiency of the 4I13/2 → 4I15/2 transition is quite high (above 70%), being the highest (97%) for the glass containing TiO2 as a modifier. The absorption and emission cross-section results for the 4I15/2 ↔ 4I13/2 transition show that the glass containing TiO2 is characterized by the largest figure of merit (FOM) for the amplifier gain and indicate this matrix as a promising new host for doping with rare-earth ions.

Structure and physical properties of Ba(PO3)2–AlF3–BaSO4 fluoro‐sulfo‐phosphate glasses

AbstractAlkali‐earth‐metaphosphate‐based fluoro‐sulfo‐phosphate M(PO3)2–AlF3–MSO4 (MPFS, M = Ca, Sr, Ba) glasses have been developed via simultaneously incorporating fluoride and sulfate into metaphosphate glass. Their glass‐forming regions were efficiently determined under the guidance of thermodynamic calculation method. The physical and structural properties of BaPFS glass were investigated in detail. Furthermore, near‐infrared spectroscopic properties of Er3+‐doped BaPFS (Er–BaPFS) glass were studied. Physical parameters, such as Abbe's number νd (55‐75) and nonlinear refractive index n2 (1.17‐1.86 × 10−13 esu), of BaPFS glass are strongly depended on P/F/S ratio. The structure of BaPFS glass gradually depolymerizes and tends to become multianionic when Ba(PO3)2 is substituted by AlF3 and BaSO4. Anion‐substitution strategy effectively modulates the property and structure of glass, providing a scheme to derive glass materials. In addition, enhanced emission at ~1.5 μm has been observed from Er–BaPFS glass along with large emission cross section (5.0‐5.5 × 10−21 cm2) and long lifetime (6.7‐7.3 ms), resulting in large figure of merit (3.46‐3.84 × 10−23 cm2·s), which is a promising candidate for solid‐state laser.

Comment on “Judd–Ofelt analysis of the Er3+ (4f11) absorption intensities in Er3+-doped garnets” [J. Appl. Phys. 93(5), 2602 (2003)

A previous paper [D. K. Sardar et al., J. Appl. Phys. 93(5), 2602 (2003)] has reported Judd–Ofelt (J–O) spectroscopic properties of Er3+ in garnets Y3Al5O12, Y3(Sc2Ga3)O12, and Gd3Ga5O12. In that paper, the possible magnetic-dipole contribution to the oscillator strength, which is non-zero for the 4I13/2 ↔ 4I15/2 (1.5 μm) transition of Er3+, has been erroneously omitted in their J–O calculation, resulting in incorrect results of relevant spectroscopic parameters. In this Comment, we point out the error, perform correct J–O analysis, and report correct results.

L-Band Wavelength-Tunable Er3+-Doped Tellurite Fiber Lasers

The spectroscopic properties of Er3+-doped tellurite glasses were investigated and a 1 wt.% Er3+-doped tellurite fiber was fabricated for L-band lasers. Wavelength-tunable fiber lasers in a linear cavity based on Littrow configuration were developed and studied with different gain fiber lengths as well as output coupling ratios. Wavelength tunable range of 38 nm from 1589–1627 nm was achieved in the experiment with a 3-m Er3+-doped tellurite fiber laser pumped at 1570 nm. A maximum output power of 52.4 mW was obtained at 1614 nm. Compared to L-band Er3+-doped silica fiber lasers, the demonstrated Er3+-doped tellurite fiber lasers exhibit much higher optical signal-to-noise ratio (>30 dB), even at the longest operating wavelength of 1627 nm. Our simulation shows that the laser wavelength can be further extended to 1634 nm if the tellurite fiber loss is improved and the fiber cavity is optimized.

Spectroscopic properties of Er:Lu2O3 crystal in mid-infrared emission

High optical quality Er3+ doped Lu2O3 single crystal with optimum doping concentration was grown by Floating zone (Fz) method. The spectral properties and Judd-Ofelt (JO) analysis were reported. The emission cross-section at 2772 nm was calculated to be 2.47 × 10−20 cm2 with FWHM of 188 nm. The fluorescence lifetime of 4I11/2 and 4I13/2 energy level was fitted to be 1.62 ms and 4.02 ms. Optimum lifetime ratio (τlow/τup) is beneficial to laser operation. Compared with reported Er3+ doped crystal, the larger spectral quality factors Q and low inversion ratio P of 7 at.% Er:Lu2O3 crystal indicate that it has a favorable laser performance for 2.8 μm laser operation.

Structural and spectroscopic properties of Er3+ doped sodium lithium borate glasses.

The trivalent erbium (Er3+) doped sodium lithium borate glass with composition (65-x)B2O3-15Na2O-10PbO-5ZnO-5Li2O-xEr2O3 have been successfully fabricated by melt-quench technique. The structural properties were investigated by X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR). The absorption and luminescence spectra of glass samples were measured to determine the spectroscopic properties. The Judd-Ofelt parameters were calculated based on absorption spectra with values of Ω2, = 4.39, Ω4 = 3.22, and Ω6 = 0.91 (×10-22 cm2) for 2.0 mol% Er3+ ion doped sodium lithium borate glass. Furthermore, radiative properties including effective bandwidth (Δλeff), radiative transition probability (AR), radiative lifetime (τR), and branching ratio (βR) were also calculated and analyzed. A strong emission band at 1532 nm was observed corresponding to 4I15/2 → 4I13/2 transition under the excitation wavelength of 528 and 976 nm. The stimulated emission cross-section (σe) and figure of merit (FWHM xσe) were calculated and compared with other glasses in order to evaluate the properties of the present samples for optical amplifier. Based on the characterization results, we found that the glass with 2.0 mol% Er3+ ion doped sodium lithium borate glass had the highest stimulated emission cross section compared to other samples and were comparable with the previous reports.

Structural, optical and thermal properties of Er3+-Ag codoped bio-silicate borotellurite glass

Abstract In this paper, thermal, structural and spectroscopic properties of Er3+-Ag+ codoped bio-silicate borotellurite [{[(TeO2)0.8 (B2O3)0.2]0.8 (SiO2)0.2}0.99 (Ag2O)0.01]1-y (Er2O3)y where y = 0.05 glass are studied. The thermal and structural studies have been conducted using differential scanning calorimetry (DSC) and X-ray diffraction (XRD) respectively so as to confirm the nature of the glass sample. The Fourier transform infrared (FTIR) has revealed the basic structural units of the glass system. Ultra violet visible (UV–Vis) spectrometer was used to measure the absorption spectrum and was analysed using Judd-Ofelt (J-O) and McCumber theory. Other important parameters such as radiative lifetime, branching ratio and transition probability are also determined from the analysis. The peak emission cross section discovered from McCumber theory is 4.9 × 10−21 cm2. This value is larger than that of phosphate, silicate and tellurite glasses. The gain band width and figure of merit are used to evaluate the application of the glass in optical amplification and solid state laser.

Growth and spectroscopic properties of Er:Lu2O3 crystal grown by floating zone method

Er3+ doped Lu2O3 single crystal with high optical quality was successfully grown by Floating zone (Fz) method. The spectral properties and Judd-Ofelt (JO) analysis were reported. The absorption cross section at 971 nm was 1.5 × 10–21 cm2. The emission cross-section at 1558 and 2742 nm was calculated to be 2.20 × 10–20 cm2 and 3.22 × 10–20 cm2, respectively. The fluorescence lifetime of 4I11/2 and 4I13/2 energy level was fitted to be 1.59 ms and 12.43 ms. Meanwhile, the positive gain cross-section was achieved in 1.5 μm and 2.8 μm with inversion ratio P = 0.5. The low inversion ratios indicate a great potential of Er:Lu2O3 crystal with good gain performance.

Complement to “Optical and Judd‐Ofelt spectroscopic study of Er3+‐doped strontium gadolinium gallium garnet single‐crystal”

AbstractIn the previous paper “Optical and Judd‐Ofelt spectroscopic study of Er3+‐doped strontium gadolinium gallium garnet single‐crystal” (J Am Ceram Soc. 2019;102:873–878), we have reported optical and Judd‐Ofelt spectroscopic properties of Er3+‐doped strontium gadolinium gallate (SrGdGa3O7) single‐crystal, and the Judd‐Ofelt study was performed on the basis of unpolarized absorption spectrum of the crystal. Present work reports the corrected unpolarized absorption spectrum and Er3+ concentration in the crystal, and hence corrected Judd‐Ofelt spectroscopic properties and cross‐section data. In addition, the polarization effect was considered in the Judd‐Ofelt analysis on the basis of polarization‐resolved absorption spectra. Effective Judd‐Ofelt parameters are presented and discussed in comparison with the results from the unpolarized spectrum, and consistent results have been obtained. This study also considers the effects of some other factors on the Judd‐Ofelt parameters. These include Er3+ concentration and selection of Er3+ absorption bands for the Judd‐Ofelt analysis.

Spectroscopic Properties of Er3+-Doped Particles-Containing Phosphate Glasses Fabricated Using the Direct Doping Method.

The effect of the incorporation of Er2O3-doped particles on the structural and luminescence properties of phosphate glasses was investigated. A series of different Er2O3-doped TiO2, ZnO, and ZrO2 microparticles was synthesized using soft chemistry and then added into various phosphate glasses after the melting at a lower temperature than the melting temperature. The compositional, morphological, and structural analyses of the particles-containing glasses were performed using elemental mapping by field emission-scanning electron microscopy (FE-SEM) with energy dispersive x-ray spectrometry (EDS) and x-ray diffraction (XRD). Additionally, the luminescence spectra and the lifetime values were measured to study the influence of the particles incorporation on the spectroscopic properties of the glasses. From the spectroscopic properties of the glasses with the composition 50P2O5-40SrO-10Na2O, a large amount of the Er2O3-doped particles is thought to dissolve during the glass melting. Conversely, the particles were found to survive in glasses with a composition 90NaPO3-(10 − x)Na2O-xNaF (with x = 0 and 10 mol %) due to their lower processing temperature, thus clearly showing that the direct doping method is a promising technique for the development of new active glasses.

Spectroscopic properties of Er3+-doped fluorotellurite glasses modified by Nb2O5 and WO3

Spectroscopic properties of Er3+-doped fluorotellurite glasses modified by Nb2O5 and WO3

Effect of modifier oxides (SrO, Al2O3, ZnO, CdO, PbO and Bi2O3) on the luminescence properties of Er3+ doped telluroborate glasses for laser and optical amplifier applications

Er3+ ion (0.5 wt%) doped telluroborate glasses were prepared with various modifier oxides through melt quenching technique. The glass samples were labeled as TBSE, TBAE, TBZE, TBCE, TBPE and TBBE corresponding to SrO, Al2O3, ZnO, CdO, PbO and Bi2O3, respectively. The effect of modifier cations on the spectroscopic properties of Er3+ ions was analyzed through FTIR, optical absorption, photoluminescence and lifetime measurements. Presence of different vibrational groups and the structural changes caused by the incorporation of various modifier ions were identified via FTIR spectra. Bonding parameter (δ) values indicate the predominant ionic nature of Er–O bond in the prepared glasses. The Judd-Ofelt (JO) parameters follow the trend of Ω2 > Ω6 > Ω4 for TBSE, TBAE, TBCE and TBPE glasses whereas TBZE, TBBE glasses posses different order such as Ω2 > Ω4 > Ω6. The visible emission spectra (excitation at 379 nm) exhibit three emission bands centered at 531, 547 and 638 nm corresponding to 2H11/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of the trivalent erbium ions. Among these emission bands, the green emission is quite intense. NIR luminescence spectra were recorded by exciting at 980 nm exhibit broad emission at 1550 nm (4I13/2→4I15/2 transition). Incorporation of different modifier cations reveals significant changes in the luminescence intensity and radiative parameters of the prepared glasses. Radiative parameters such as transition probability, effective bandwidth, stimulated emission cross-section and branching ratio have been estimated for 4S3/2→4I15/2 and 4I13/2→4I15/2 transitions. Emission cross-section (σe) and the gain coefficient (G) for the 4I13/2→4I15/2 transition have been estimated through McCumber theory. Decay profile of 4S3/2 and 4I13/2 excited states of Er3+ ion is of bi-exponential nature. It indicates that more than one relaxation mechanisms are operating in decay of the excited state of Er3+ ions. Glasses containing bismuth (TBBE) are endowed with higher stimulated emission cross-section (71.74 × 10–22 cm2) and gain bandwidth product (638 × 10–28 cm3) for 4I13/2→4I15/2 transition. The present study suggests the Er3+ ions doped telluroborate glass with bismuth cation to be best candidate for green laser and broadband optical amplifier applications.

Spectroscopic properties of Er3+/Yb3+ co-doped fluorophosphate glasses for NIR luminescence and optical temperature sensor applications

A series of Er3+/Yb3+ co-doped fluorophosphate glasses with varying YbF3 concentration were prepared by a high temperature melt quenching technique. Absorption and emission cross-sections were determined by using the McCumber theory. The larger emission cross-section (9.86×10−21cm2) and longer fluorescence lifetime (12.37ms) were obtained for the 4I13/2→4I15/2 transition of ABS3Er4Yb glass. The sensitivity and temperature of the maximum sensitivity were evaluated by the fluorescence intensity ratio method from the measured upconversion spectra. The results were discussed and compared to the other reported glasses.

Efficient diode-pumped Er:KLu(WO4)2 laser at ∼1.61 μm.

We report on an efficient diode-pumped continuous-wave erbium-doped monoclinic double tungstate laser. It is based on a 1at.% Er3+:KLu(WO4)2 (Er:KLuW) crystal cut along the Ng optical indicatrix axis. The Er:KLuW microchip laser, diode pumped at 0.98μm, generates 268mW at 1.610μm with a slope efficiency of 30%. The output is linearly polarized (E||Nm), and the laser beam is nearly diffraction limited (Mp,m2<1.1). Spectroscopic properties of Er3+ in KLuW are also presented. The stimulated-emission cross-section σSE is 0.46×10-20 cm2 at ∼1.609 μm for E||Nm. The microchip Er:KLuW laser outperforms the commercial Er,Yb:glass.

Er3+掺杂的锗碲酸盐玻璃结构及光谱性能研究

Er³⁺掺杂的锗碲酸盐玻璃结构及光谱性能研究