Spectral Properties Of Er Research Articles

Structure and Spectral Properties of Er3+-Doped Bismuth Telluride Near-Infrared Laser Glasses.

TeO2-Bi2O3-B2O3-ZnO laser glasses doped with Er3+ were synthesized through an optimized melt-quenching method. The absorption spectra at 808 nm LD pumping were studied. Various spectral tests and data analyses indicate that the maximum fluorescence emission intensity can be obtained when the Er3+ doping concentration reaches 2%. In this case, the emission cross-section can reach up to 9.12 × 10-21 cm2 and the gain coefficient at 1.55 μm is 6.17 cm-1. Simultaneously, the sample has a lower phonon energy in the high-frequency band at 1077 cm-1, which reduces the probability of non-radiative relaxation. The calculated energy transfer coefficient CD-A is 13.8 × 10-40 cm6/s, reflecting the high cross-relaxation probability of Er3+ in the sample, which promotes the luminescence of 1.55 μm and favors the emission in the near-infrared region. The comprehensive results demonstrate that the prepared Er3+-doped bismuth telluride laser glass can be used as a promising and high-quality gain material for near-infrared lasers.

Continuous tuning of optical transition properties and phonon spectrum in Er3+ doped germano-tellurite glass system

With the development of science and the progress of technology, novel and advanced rare earth ions doped luminescent materials with higher performance are demanded in the both emerging and traditional applications. Understanding the rules for tuning the spectroscopic properties of these materials is crucial for their development. However, achieving precise control over the optical properties of rare earth doped materials using traditional design and synthesis methods, such as altering dopants and their concentrations or modifying the preparative conditions, still remains challenging. This work aims to adjust the optical transition characteristics of Er3+ doped germano-tellurite glasses by changing the glass components. First, the Er3+ doped germano-tellurite glass series were synthesized using a high-temperature melt-quenching method at optimized melting temperatures. The tuning of band gap energy and refractive index of the glasses were revealed, and it was found that both of them can be monotonically and continuously tuned by changing the glass composition. The optical transition intensity parameters of Er3+ in the glasses were calculated in the framework of traditional three-parameterized Judd-Ofelt theory using the absorption spectra, and furthermore the corresponding optical transition parameters including radiative transition rates and intrinsic lifetimes for some interested levels were alsoconfirmed. The results demonstrated that the optical transition parameters could be efficiently modulated by changing the glass composition, indicating that the spectral properties of Er3+ doped germano-tellurite glasses can be tuned for the practical applications. The reliability of the deduced tuning rule was validated by comparing the theoretical and experimental transition rate ratios of 2H11/2 → 4I15/2 to 4S3/2 → 4I15/2. Furthermore, the tuning regulation of the phonon spectra in relation to the glass composition was discovered, showing a concordance between theoretical predictions and experimental results. From the above facts, it can be concluded that the optical transition properties of Er3+ in germano-tellurite glasses can be substantially adjusted by modifying the glass composition. This work provides a new perspective for designing and developing novel luminescent materials to meet specific application needs.

Growth and Spectral Properties of Er3+ and Yb3+ Co-Doped Bismuth Silicate Single Crystal

Rare-earth-doped bismuth silicate (Bi4Si3O12, BSO) crystal is a multifunctional material for scintillation, LED, and laser applications. In the present study, Er3+ and Yb3+ ions co-doped bismuth silicate crystals were grown by a modified vertical Bridgman method, and their spectral properties were investigated for the first time. Transparent Er/Yb: BSO single crystal up to Φ 25 mm × 30 mm was obtained. The segregation coefficient of the Er/Yb: BSO crystal was measured to be 0.96 for Er3+ ions and 0.91 for Yb3+ ions. Absorption and fluorescence spectra had been recorded in the range of 200–1700 nm. The absorption cross section was calculated to be 6.96 × 10−20 cm2 at 976 nm with the full width at half maximum (FWHM) of 8 nm, and the emission cross section was 0.9771 × 10−20 cm2 at 1543 nm with FWHM of 16 nm. The fluorescence decay curve was measured at 976 nm excitation. By linear fitting, the fluorescence lifetime of the upper 4I13/2 level of Er3+ was 8.464 ms at room temperature. Compared with Er3+ ion-doped bismuth silicate crystal (Er: BSO), the Er/Yb: BSO crystal has a wider FWHM and larger absorption cross section. The results indicate that the Er/Yb: BSO crystal is a potential lasing crystal.

Relationship between glass structure and spectroscopic properties in Er3+/Yb3+/Al3+/P5+-doped silica glasses

In this study, Er3+/Yb3+/Al3+/P5+-doped silica (simplified as EYAPS) glasses with different P/Al ratios ranging from zero to infinity were fabricated via the sol-gel method combined with high-temperature sintering. The absorption, emission and fluorescence lifetime of Yb3+ and Er3+ ions as well as the energy transfer efficiency from Yb3+ to Er3+ ions were recorded. The composition-dependent macroscopic properties were correlated to the glass structures, and probed by pulse electron paramagnetic resonance (EPR) and Raman spectroscopy. Results show that the spectral properties of Er3+ and Yb3+ ions and their local environment as well as the global glass network structure of EYAPS glasses are strongly dominated by the P/Al ratio. With the increase of the P/Al ratio, pulse EPR shows that rare earth ions gradually moved from a silicon and aluminum rich environment to a phosphorus rich environment. Raman spectroscopy shows that the maximum phonon energy of EYAPS samples gradually increases from 1200 to 1326 cm−1 due to the formation of AlPO4-like units and P = O double bonds. These structural changes lead to a gradual increase of peak absorption and emission cross sections of Er3+ ions at 1.5 µm, as well as the energy transfer efficiency of 2F5/2 level of Yb3+ to 4I11/2 level of Er3+ ions.

Enhanced 2.7 μm continuous-wave emission of Er,Pr:Lu2O3 crystal

The high optical quality Er:Lu2O3 and Er,Pr:Lu2O3 crystals were grown by Floating zone method. The spectral properties of Er:Lu2O3 and Er,Pr:Lu2O3 crystals were investigated. After co-doping small concentration of Pr3+, the depopulated influence of Pr3+ to the NIR emission was much stronger than the MIR emission. The near-infrared and up-conversion fluorescence were significantly quenched. Moreover, the fluorescence lifetime of 4I13/2 abviously decreases from 4.02 ms to 1.71 ms in 7% Er, 0.05% Pr: Lu2O3 crystal, and the lifetime ratio is 1.63 with large fluorescence lifetime of 4I11/2 which is desirable lifetime ratio in these crystals. Thus, the spectral performance was significantly improved by co-doping 0.05 at.% of Pr3+. The high laser performance at 2.7 μm of 7% Er, 0.05% Pr: Lu2O3 crystal is expectable.

Cracking mechanism and spectral properties of Er,Yb:CaGdAlO4 crystals grown by the LHPG method

High quality Er,Yb:CaGdAlO4 (Er,Yb:CALGO) single crystals with a diameter around 1 mm were successfully grown and investigated for the first time by the laser heated pedestal growth (LHPG) method.

Yb3+含量对掺Er3+铝酸盐玻璃光谱性质的影响

Yb3+含量对掺Er3+铝酸盐玻璃光谱性质的影响

Effect of Yb co-doping on the spectral properties of Er:YVO4 single crystal: A Judd Ofelt analysis

Single crystals of 0.7 at% Er:YVO4 co-doped with varied concentrations of Yb (1.5, 3.0 and 8.0 at%) were grown by optical floating zone technique. The absorption spectra of the grown crystal are characterized by the prominent absorption at 985 nm due to Yb ion and multiple absorption due to Er ions. The overall characteristic absorption for π-polarization (E||c) is stronger than that for σ-polarization (E┴c) due to alignment of dipole moments along c-direction. The line strength of all the transitions of Er ions decreases as the doping concentration of Yb increases. Judd Ofelt parameter Ω2, which strongly depends on the environment of ligand, decreases with increasing Yb concentration in the lattice. The value of spectroscopic quality factor was found to be nearly invariant (~ 1.80) with respect to the Yb doping concentration but better than that for Er doped YVO4 (~1.31) [1]. The radiative lifetime and emission cross-section of 4I13/2→4I15/2 transition of Er ions was also found to be independent of Yb doping concentration. This is one of the biggest advantages of Yb co-dopant as a good sensitizer in the Er:YVO4 as it results in high population density in upper level of Er ions making it. The emission cross-section of 4I13/2→4I15/2 line for excitation at 985 nm is ~ 2.33 × 10−20 cm2. Further, the values of emission cross-section for both the excitation at 808 nm (Er absorption line) and 985 nm (Yb absorption line) were found nearly same.

Spectral Properties of Er3+/Tm3+ Co-Doped ZBLAN Glasses and Fibers.

A series of Er3+/Tm3+ co-doped fluoride (ZBLAN) glasses and fibers was prepared and their fluorescence spectra was measured under excitation at 793 nm and 980 nm. Correlation between the self-absorption effect of rare-earth ions and the shift of the emission peak was investigated. With the increasing length of fiber, the emission peaks red-shift when self-absorption occurs at the upper level of emission transition or blue-shift when that occurs at the lower level. As a result of the strong self-absorption effect, Er3+/Tm3+ co-doped fibers mainly yield 1390–1470, 1850–1980, and 2625–2750 nm emissions when excited at 793 nm, and 1480–1580, 1800–1980, and 2625–2750 nm emissions when excited at 980 nm. Further, a broadband emission in the range of 1410–1580 nm covering the S + C communication band was obtained by the dual-pumping scheme of 793 nm and 980 nm. Results suggest that the dual-pumping scheme would be more effective and important for an Er3+/Tm3+ co-doped fiber amplifier working in the S + C communication band.

Elaboration and characterization of a KCl single crystal doped with Er3+

This paper reports the growth and spectral properties of Er3+ doped KCl single crystals, the KCl:Er3+ with dimension of 20mm in diameter and 100mm in length were obtained by the Czochralski (Cz) melting solution growth method. Crystallographic structure using X-ray diffraction pattern analysis (XRD), the optical absorption spectra in the wavelength range from 200 to 1800nm, the photoluminescence (PL) and the radioluminescence spectra of KCl single crystal doped with Er3+ ions were measured. The results reveal that the Er3+ is incorporated in the KCl host and occupy substitutional K+ sites position in the crystal, the Er3+ elements have a good optical properties and a new scintillators KCl:Er3+ were successfully synthesized with the Czochralski (Cz) technique.

Spectral properties of Er3+-doped CaGdAlO4 crystal for laser application around 1.55μm

Abstract Room-temperature polarized spectral properties of the Er:CaGdAlO 4 crystal are reported. The Judd–Ofelt theory was applied to analyze the polarized absorption spectra and then calculate the spontaneous emission probabilities, radiative lifetimes, and branch ratios. Room-temperature fluorescence lifetimes of the 4 I 13/2 , 4 I 11/2 , 4 F 9/2 , and 4 S 3/2 multiplets for Er 3+ ions were measured. Stimulated emission cross-sections of the 4 I 13/2 → 4 I 15/2 transition obtained by the Fuchtbauer–Ladenberg formula and the reciprocity method were compared. The results show that the Er:CaGdAlO 4 crystal may be a potential gain medium for a low-threshold 1.55 μm laser.

Growth and spectral properties of Er3+/Tm3+ co‐doped LiYF4 single crystal

High quality Er3+/Tm3+:LiYF4 single crystals were grown by a Bridgman method. The absorption spectra and luminescent properties of the crystals were studied to characterize the effect of Tm3+ on the spectroscopic properties upon excitation of an 800 nm laser diode. The broaden 1.5 μm and the enhanced 2.7 μm emission were observed in the Er3+/Tm3+ co‐doped LiYF4 single crystals. Meanwhile, the up‐conversion and 1.5 μm emission intensities from Er3+ decrease with increasing the ratio of Tm3+ to Er3+. The energy transfer processes between Tm3+ and Er3+ in the Er3+/Tm3+ co‐doped samples were analyzed. The energy transfer efficiency ηETE from Er3+ to Tm3+ is calculated. The highest ηETE of 65.30% for the sample with 0.296 mol% of Er3+, 0.496 mol% of Tm3+ concentration was obtained. The present work indicates that Er3+/Tm3+ co‐doped LiYF4 single crystal can be a promising material for the potential application in infrared devices.

铒铋共掺硼酸盐玻璃的光谱特性

铒铋共掺硼酸盐玻璃的光谱特性

Effects of Na<sup>+</sup> on Spectral Properties of Er<sup>3+</sup>: CaF<sub>2</sub> Transparent Ceramic

Er3+, Na+-co-doped CaF2 transparent ceramics with Er3+ dopant concentration of 5at% and Na+ of 0, 0.5, 1.0 and 1.5at% were fabricated by the vacuum hot pressing method. Absorption spectra, emission spectra and fluorescence lifetimes were measured at room temperature to study the effects of Na+ on the spectral properties of Er3+: CaF2 transparent ceramic. The results showed that after introducing Na ion into Er3+: CaF2 transparent ceramics, charge-neutralized Er3+-Na+ structure formed which prevented Er3+ from clustering, the absorption intensity of ceramics decreased with the increase of Na+ concentration, but the spectroscopy and photoluminescence properties of Er3+ in CaF2 transparent ceramic could be modulated by adjusting the concentration of Na+. Co-doping Na+ to increase fluorescence lifetime should have an optimal value.

Growth, Thermal and Spectral Properties of Er3+-Doped and Er3+/Yb3+-Codoped Li3Ba2La3(WO4)8 Crystals

This paper reports the growth and spectral properties of Er3+-doped and Er3+/Yb3+-codoped Li3Ba2La3(WO4)8 crystals. The Er3+: Li3Ba2La3(WO4)8 crystal with dimensions of 56 mm×28 mm×9 mm and Er3+/Yb3+: Li3Ba2La3(WO4)8 crystal with dimensions of 52 mm×24 mm×8 mm were obtained by the top-seeded solution growth (TSSG) method. Thermal expansion coefficients and thermal conductivity of both crystals were measured. The spectroscopic characterizations of both crystals were investigated. The spectroscopic analysis reveals that the Er3+/Yb3+: Li3Ba2La3(WO4)8 crystal has much better optical properties than the Er3+: Li3Ba2La3(WO4)8 crystal, thus it may become a potential candidate for solid-state laser gain medium material.

Growth and spectral properties of Er3+/Yb3+ and Ce3+/Er3+/Yb3+‐doped NaGd(MoO4)2 crystals

AbstractThis paper reports on the growth and spectroscopic properties of Er3+/Yb3+:NaGd(MoO4)2 and Ce3+/Er3+/Yb3+:NaGd(MoO4)2 crystals. Er3+/Yb3+:NaGd(MoO4)2 and Ce3+/Er3+/Yb3+:NaGd(MoO4)2 crystals were grown by the Czochralski method. The investigated polarized spectroscopic properties of both crystals revealed that when the Ce3+ ion was introduced into Ce3+/Er3+/Yb3+:NaGd(MoO4)2 crystal, it could enhance the 1.5 µm fluorescence intensity and decrease the fluorescence lifetime of Ce3+/Er3+/Yb3+:NaGd(MoO4)2 crystal. To sum up the spectral properties of Ce3+/Er3+/Yb3+:NaGd(MoO4)2 crystal, it may be regarded as a potential 1.5 µm Er3+ laser crystal material.

Spectral properties of Er3+ in alkali-zinc-tellurite, barium-tellurite-molybdate, and fluoride glasses

Glasses of three compositions—TeO2 · ZnO · N2O (TZN), where N is Li, Na, or K; TeO2 · MoO3 · BaO (TMB); and ZrF4 · BaF2 · LaF3 · AlF3 · NaF (ZBLAN)—activated by Er3+ or Yb3+ and Er3+ ions were synthesized and investigated. For the ZBLAN glass, the brightest luminescence of Er3+ ions in the visible range was observed under excitation by the irradiation of a diode laser with the generation wavelength 0.98 μm. The TZN glass is not inferior in the intensity of luminescence with the wavelength 1.55 μm to the TMB glass, having phonons of higher energy than those for the TZN glass (940 and 740 cm−1, respectively). A glass was prepared with a high content of molybdenum oxide. The possibility to increase the up-conversion efficiency in tellurite glasses is considered.

Growth and spectral properties of Er3+:Ca9La(VO4)7 crystal

Er3+:Ca9La(VO4)7 crystal with dimensions of φ24×22 mm3 has been successfully grown by the Czochralski method. The spectral properties of Er3+:Ca9La(VO4)7 crystal were investigated. The oscillator strength parameters Ωt (t = 2, 4 and 6) in Er3+:Ca9La(VO4)7 crystal were calculated to be: Ω2 = 9·05×10−20 cm2, Ω4 = 3·34×10−20 cm2 and Ω6 = 2·1×10−20 cm2 for π‐polarisation and Ω2 = 23·88×10−20 cm2, Ω4 = 3·92×10−20 cm2 and Ω6 = 1·89×10−20 cm2 for σ‐polarisation. The emission cross‐sections σem for π‐polarisation and σ‐polarisation at 1534 nm are 0·98×10−20 and 1·23×10−20 cm2 respectively. The fluorescence lifetime and radiative lifetime of the 4I13/2→4I15/2 transition are 3·93 and 2·69 ms respectively. These results show that Er3+ doped Ca9La(VO4)7 crystals may be regarded as 1·55 μm laser gain medium materials.

Temperature gradient controlled growth and optical properties of Er:BaY2F8 crystals

AbstractSingle crystals of Erbium (Er) doped BaY2F8 have been obtained by the temperature gradient technique (TGT). No‐seed‐grown crystal of Er:BaY2F8, with the dimensions up to several centimeters, was obtained by self‐crystallization. The optimizations of various growth parameters were systemically investigated. The results indicated that the temperature gradient of 6‐7 K/mm and the cooling velocity less than 6 K/h were suitable for the crystal growth. The XRD data and the investigations on the growth striations by a stereo polarization microscope displayed that the [001] direction is the dominating direction for the crystal growth. The crystal grown by TGT often cracks along with the (100) plane, which is caused by the excessive decrease of the temperature during the crystal growth, for there is a rapid change in the thermal expansion curve of the BaY2F8 crystal in the temperature range from 800 °C to 900 °C. The spectral properties of Er:BaY2F8 single crystals have been studied and the effects of frequency up‐conversion of the crystals are reported. Spectral data suggest that the quality of Er:BaY2F8 crystal obtained by TGT method is good and the crystal has the potential application in laser devices. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Infrared-to-Visible Upconversion Emissions in Er<sup>3+</sup> Doped TeO<sub>2</sub>-Based Oxyhalide Glasses

The fluorescence and up-conversion spectral properties of Er3+-doped TeO2-ZnO and TeO2-ZnO-PbCl2 glasses suitable for developing optical fiber amplifier and laser have been fabricate and characterized. Strong green (around 527-550 nm) and red (around 661 nm) up-conversion emissions under 977 nm laser diode excitation were investigated, corresponding to 2H11/2, 4S3/2, ® 4I15/2 and 4F9/2 ® 4I15/2 transitions of Er3+ ions respectively, have beenobserved and the involved mechanisms have been explained. The dependence of up-converted fluorescence intensity versus laser power confirm that two-photons contribute to up-conversion of the green-red emissions. The novelty of this kind of optical material has been its ability in resisting devitrification, and its promising optical properties strongly encourage for their further development as the rare-earth doped optical fiber amplifiers and upconversion fiber laser systems.