Emission Cross-section Of Er3 Research Articles

Optical transition and near-infrared upconversion luminescence properties of YNbO4: Er3+, Yb3+ phosphors

Optical transition and near-infrared upconversion luminescence properties of Er3+ single-doped and Er3+, Yb3+ co-doped YNbO4 phosphors are reported. Based on the framework of Judd-Ofelt theory and modified Judd-Ofelt calculation method, the optical transition properties of Er3+ and Yb3+ ions in YNbO4: Er3+, Yb3+ sample were studied, respectively. The calculated results showed that the absorption cross-section of Er3+ ion at ∼1550 nm is larger than that at ∼980 nm in YNbO4: Er3+ phosphor. And, the absorption cross-section of 2F7/2 → 2F5/2 transition of Yb3+ in YNbO4: 15.0 mol% Er3+, 15.0 mol% Yb3+ sample was calculated to be 138.70 × 10−20 cm2. According to the emission cross section of Er3+ (4I11/2 → 4I15/2) and the absorption cross section of Yb3+ (2F7/2 → 2F5/2), the energy transfer rates from Er3+ to Yb3+ were quantitatively analyzed via the Föster-Dexter model. Furthermore, 1550 nm was selected as the excitation wavelength, the near-infrared upconversion emission spectra of YNbO4: Er3+, Yb3+ samples were measured. It was found that the sample has strong emission at ∼980 nm and the emission intensity was still enhanced with the incorporation of Yb3+.

Tailoring of communication band luminescence for super broadband optical amplifier based on [formula omitted] co-doped nanoporous silica glass

We report on a series of Er3+/Yb3+/P5+ co-doped silica glass from nanoporous silica glass based on glass phase separation technology. The optical properties of the Er3+/Yb3+/P5+ co-doped glasses were investigated. Measurements showed that phosphorus can promote energy transfer from Yb3+ ions to Er3+ ions while suppressing the energy transfer from Er3+ ions to Yb3+ ions and efficiently suppressing the amplified spontaneous emission (ASE) from Yb3+ ions at 1030 nm. Additionally, the luminescence of Er3+ (I413/2→I415/2) was greatly extended under 976 nm laser excitation, and the full width at half maximum (FWHM) of Er3+ (I413/2→I415/2) was measured to be up to 72 nm and enables the luminescence peak redshifted. The emission cross section of Er3+ (I413/2→I415/2) was calculated to be 1.6*10−20cm2, one order higher than that of other silica glasses. It is suggested that the Er3+/Yb3+/P5+ co-doped silica glasses based on nanoporous silica glass present great potential for broadband amplification.

Er(3+)-doped transparent glass ceramics containing micron-sized SrF2 crystals for 2.7 μm emissions.

Er3+-doped transparent glass ceramics containing micron-sized SrF2 crystals were obtained by direct liquid-phase sintering of a mixture of SrF2 powders and precursor glass powders at 820 °C for 15 min. The appearance and microstructural evolution of the SrF2 crystals in the resulting glass ceramics were investigated using X-ray diffraction, field-emission scanning electron microscopy and transmission microscopy. The SrF2 crystals are ~15 μm in size and are uniformly distributed throughout the fluorophosphate glass matrix. The glass ceramics achieve an average transmittance of 75% in the visible region and more than 85% in the near-IR region. The high transmittance of the glass ceramics results from matching the refractive index of the SrF2 with that of the precursor glass. Energy dispersive spectroscopy, photoluminescence spectra, and photoluminescence lifetimes verified the incorporation of Er3+ into the micron-sized SrF2 crystals. Intense 2.7 μm emissions due to the 4I11/2 → 4I13/2 transition were observed upon excitation at 980 nm using a laser diode. The maximum value of the emission cross section of Er3+ around 2.7 μm is more than 1.2 × 10−20 cm2, which indicates the potential of using transparent glass ceramics containing micron-sized SrF2 crystals for efficient 2.7 μm lasers and amplifiers.

1.53 μm emission properties in Er3+ doped Y2O3 and Nb2O5 modified germanate glasses for an optical amplifier

Er3+ doped Y2O3 and Nb2O5 modified germanate glasses have been reported which possesses excellent thermal stability. Near infrared emission characteristics upon excitation of a conventional 980nm laser diode have been investigated. According to absorption spectra and refractive index, Judd–Ofelt intensity parameters, spontaneous radiative transition probabilities, radiative lifetimes and stimulated emission cross sections have been calculated and discussed. These results indicate that the predicted spontaneous transition probability and emission cross section of Er3+:4I13/2→4I15/2 transition in developed glasses can reach as large as 192.39s−1 and 7.14×10−21cm2, respectively. Hence, germanate glasses with superior performances might be a useful material for applications in optical amplifiers around 1.53μm.

Absorption intensities and emission cross section of Er3+ in Sc2O3 transparent ceramics

Spectroscopic investigation of Er3+ doped Sc2O3 transparent ceramics was performed in order to assess its potential as a laser material for different emission wavelengths. The Judd–Ofelt intensity parameters for the f-f transitions of the C2-symmetry center of Er3+ in Sc2O3 transparent ceramics, inferred from the room temperature absolute intensities of the absorption bands in the 370–1600nm range, are Ω2=3.57×10−20cm2, Ω4=1.61×10−20cm2, and Ω6=0.79×10−20cm2. These parameters are comparable to those reported for Er3+ in other sesquioxide single crystals. The Judd–Ofelt intensity parameters are used to determine the emission probabilities, radiative lifetimes, and branching ratios of the different Er3+ transitions. The emission cross sections of the potential laser transitions at ∼1.5μm were determined using the reciprocity method, and the potential laser gain versus wavelength for the I13∕24→I15∕24 was analyzed.

宽带短光纤放大器用掺铒磷碲酸盐玻璃的研究

Er3+-doped phosphor-tellurite glass for broadband short-length Er3+-doped fiber amplifier (EDFA) is fabricated and characterized. The differential value (Delta T) of onset crystalline temperature (Tx) and glass transition temperature (Tg) is 206 centigrade. The stimulated emission cross section of Er3+ is calculated from absorption spectrum by McCumber theory and is 0.87*10^(-20) cm^2 at 1532 nm. A broad 1.5-micron fluorescence spectrum with 54-nm full-width at half maximum (FWHM) is demonstrated. Especially, the maximum phonon energy of undoped phosphor-tellurite glass is 1100 cm^(-1), which restricts the upconversion luminescence. It is possible to pump efficiently at 980 nm. These results indicate Er3+-doped phosphor-tellurite glass is suitable for fabricating broadband short-length EDFA.

Investigation of spectral properties and thermal stability of Er3+/Yb3+ co-doped tungsten-tellurite glasses

Er3+/Yb3+ co-doped tungsten-tellurite glasses, 65TeO2 -25WO3-10RmOn(RmOn= PbO,BaO), (65+x) TeO2-(25-x)WO3- 10La2O3(x=0,5,10),(60+x)TeO2-(30-x)WO3-10Bi2O3(x=0,5,10) have been prepared. The thermal stability and spectral properties, such as absorption spec tra, emission spectra and lifetimes of the 4I13/2 level of Er3+ were investigated. Results obtained show that tungsten-telluri te glasses have good thermal stability. All the glass samples except the Bi2O3-containing g lasses show no onset temperature of crystallization (Tx), indicating that they are stable for fiber drawing. Three intensity parameters Ωt(t= 2,4, 6) were calculated by Judd-Ofelt theory. It is shown that Ω2 is domi nated b y the covalency between the Er3+ and O2-, the effect of as ymmetry in the local structures around the Er3+ ions on Ω2 can be neglected. The full width at half maximum (FWHM=71—77 nm) of the 4I 13/2→ 4I15/2 emission and lifetimes of 4I 13/2 level(τm= 3—3.4 ms) of Er3+ ions were measured. The emission cross-section ( σpeak=068—103×10-20 cm2) of the 4I13/2→4I15/2 transitio n of Er3+ ions were calculated according to the McCum ber the ory. The FWHM and emission cross-section of Er3+ ions at 1.5 μm ba nd in d ifferent glass hosts were compared. The results show that tungsten-tellurite gla ss will be the promising host material for 1.5 μm broadband amplification.

Preparation and spectral characterization of new Er 3+ -doped TeO 2 –B 2 O 3 –WO 3 –ZnO–ZnS glasses

Erbium-doped TeO2-based oxysulfide glasses have been prepared in argon atmosphere in graphite crucibles. The results of thermal analysis and spectroscopic properties of Er3+ have been studied in terms of sulfide influence. As a function of composition, we have measured principally the optical absorption, spontaneous emission and lifetime of the materials. Judd–Ofelt theory was introduced to calculate bandwidth and emission cross-section of Er3+. The results demonstrate that addition of sulfide in tellurite glasses results in broad emission spectra, with high emission cross-section, slightly low emission lifetime and a comparatively high thermal stability as pure oxide glasses.

Thermal Stability and Spectroscopic Properties of NewEr3+/Yb3+-Codoped Tellurite Glasses

A series of new Er3+/Yb3+-codoped70 TeO2–5 Li2O–(25-x)B2O3–xGeO2 (TLBG,x = 0, 5, 10, 15, 20 mol%) glasses are prepared.The thermal stability and spectroscopic properties of TLBG glasses arestudied. It is found that these glasses have the better thermalstability ((Tx−Tg)>150 degrees C) comparedwith 75 TeO2–20 ZnO–5Na2O (TZN) glass. The fluorescencefull width at half maximum (FWHM) is about 77 nm, while the emissionintensity and the quantum efficiency of the 4I13/2level of Er3+ increase with the increasing GeO2 content.The maximum quantum efficiency and stimulated emission cross-section ofEr3+ calculated from the McCumber theory are 93.82% and9.0×10−21 cm2, respectively. The products of FWHMand σepeak of Er3+ in TLBG glasses are larger thanthose in other reported glasses. The obtained data indicate that thiskind of TLBG glasses is a promising candidate host material forEr3+-doped broadband amplifiers.