Spectroscopic and structural properties of YbF3-doped fluorophosphate glasses

Compositional influences on the spectroscopic properties of Yb3+ and the structural variations with the introduction of YbF3 were studied in fluorophosphate glasses. Emission cross-section (sigma(emi)) and gain coefficient (sigma(emi) x tau(f)) were calculated which exhibit maximum at RF2 = 33 mol%. YbF3 has an important effect on the glass forming ability of fluorophosphate glasses when RF2 is over 36 mol%. The study of Raman spectra showed big differences on the glass structure between non-Yb3+ and Yb3+ -doped glasses. The main building units in Yb3+-doped samples are metaphosphate groups, pyrophosphate groups (P-2(O,F)(7), PO3F), Al[F-6] +Al[O,F](6) and F3Al-O-AlF3 while those of the non-Yb3+-doped glasses are monophosphate group P(O,F)(4), little pyrophosphate group, Al[F-4] + Al[F-6] + Al[O,F](4) + Al[O,F](6) and F3Al-O-AlF3, which means Yb3+ ions contribute to a better glass polymerization and network uniformity. (C) 2004 Elsevier B.V. All rights reserved.

Broadband amplification and upconversion luminescence properties of Er3+/Yb3+ co-doped fluorophosphate glass

Broadband and upconversion properties were studied in Er3+/Yb3+ co-doped fluorophosphate glasses. Large Omega(6) and S-ed/(S-ed + S-md) values and the flat gain profile over 1530-1585 nm indicate the good broadband properties of the glass system. And a premise of using Omega(6) as a parameter to estimate the broadband properties of the glasses is proposed for the first time to our knowledge. Results showed that fluorescence intensity, upconversion luminescence intensity, the intensity ratio of red/green light (656 nm/545 nm) are closely related to the Yb3+:Er3+ ratio and Er3+ concentration, and the corresponding calculated lifetime of F-4(9/2) and S-4(3/2) states for red and green upconversion samples proves this conclusion. The upconversion mechanism is also discussed. (c) 2005 Elsevier Ltd. All rights reserved.

Novel erbium-doped TeO2-based oxysulfide glasses: thermal and spectroscopic properties

Er3+-doped TeO2-based oxysulfide glasses have been prepared in argon atmosphere in carbon crucibles. The thermal analysis and spectroscopic properties of Er (3+) have been considered in terms of sulfide influence. As a function of composition, we have principally measured optical absorption, spontaneous emission and lifetime measurements. Judd-Ofelt theory was introduced to calculate bandwidth and emission cross-section. The results show the product FVMM x sigma(c) increase from 476.8 8 to 635.04 10(-21) cm(2) nm evidently with the addition of 10 mol% PbS into tellurite glass, which indicates a perfect effect on spectra property of Er3+ ions. (C) 2004 Elsevier B.V. All rights reserved.

Effects of PbF2 on the spectroscopic, lasing and structural properties of Yb3+-doped fluorophosphate glass

Effect of PbF2 on Yb3+ -doped fluorophosphate glasses is studied. Results indicate that proper amount of PbF2 has absolute advantages in improving the crystallization stability of fluorophosphate glasses. T, value performs a decreasing and increasing tendency with 25 mol% PbF2 as the turning-point. And the spectroscopic properties such as absorption and emission cross section, effective fluorescence linewidth are apparently enhanced with PbF2 over 25 mol%. Lasing parameters beta, I-sat and I-min increase slightly with the addition of PbF2. Raman analysis proves that over 20 mol% PbF2, destroys the phosphate vibration groups greatly. (c) 2005 Elsevier Ltd. All rights reserved.

Effect of F- ions on physical and spectroscopic properties of Yb3+-doped TeO2-based glasses

The effects of F- ions on physical and spectroscopic properties of the Yb3+ in tellurite glass system are investigated. The results show that the glass system takes on good thermal stability with the content of ZnF2 lower than 15 mol%, both the emission cross-section and the fluorescence lifetime of Yb3+ ions increase evidently which indicate that such oxyfluoride tellurite glass system is a promising laser host matrix for high power generation. FT-IR spectra were used to analyze the effect of F- ions on the structure of tellurite glasses and OH- groups in this glass system. Analysis demonstrates that addition of fluoride decreases the symmetry of the structure of tellurite glasses which increases the emission cross-section and removes the OH- groups, and which improves the measured fluorescence lifetime of Yb3+ ions. (c) 2004 Elsevier B.V. All rights reserved.

Spectral properties and stability of Er3+-doped TeO2-WO3 glass

Er3+-doped TeO2-WO3 glass was fabricated and characterized by absorption spectrum, fluorescence spectrum, Raman spectrum and stability. The Judd-Ofelt parameter ohm(t)(t = 2, 4, 6) were calculated from the absorption spectrum by the Judd-Ofelt theory. The fluorescence spectrum indicates that the fluorescence width at half-maximum (FWHM) is 66nm. The stimulated emission cross-section of Er3+ in TeO2-WO3 glass at 1532 nm was calculated to be 0.80 x 10(-20) cm(2) by McCumber theory. The phonon energy of TeO2-WO3 glass is found to be 931 cm(-1). The difference between crystallization onset temperature and glass transition temperature Delta T is 112 degrees C. These results show that Er3+-doped TeO2-WO3 glass has higher stability and good spectral properties, which were useful for broadband amplifier. (c) 2005 Elsevier B.V. All rights reserved.

Spectroscopic properties and thermal stability of Er3+-doped tungsten-tellurite glass for waveguide amplifier application

Tungsten-tellurite glass with molar composition of 60TeO(2)-30WO(3)-10Na(2)O has been investigated for developing planar broadband waveguide amplifier application. Spectroscopic properties and thermal stability of Er3+-doped tungsten-tellurite glass have been discussed. The results show that the introduction Of WO3 increases significantly the glass transition temperature and the maximum phonon energy. Er3+-doped tungsten-tellurite glass exhibits high glass transition temperature (377 degrees C), large emission cross-section (0.91 x 10(-20) cm(2)) at 1532 nm and broad full width at half maximum (FWHM), which make it preferable for broadband Er3+-doped waveguide amplifier application. (c) 2005 Elsevier B.V. All rights reserved.

The effect of OH- groups on the spectroscopic properties of erbium-doped tellurite glasses

A series of five different concentration erbium-doped tellurite glasses with various hydroxl groups were prepared. Infrared spectra of glasses were measured. In order to estimate the exact content of OH- groups in samples, various absorption coefficients of the OH- vibration band were analyzed under the different oxygen bubbling times. The absorption spectra of the glasses were measured, and the Judd-Ofelt intensity parameters Omega(i) of samples with the different erbium ions concentration and OH- contents were calculated on the basis of the Judd-Ofelt theory. The peak stimulated emission cross-section of (I13/2 ->I15/2)-I-4-I-4 transition of the samples was finally calculated by using the McCumber theory. The fluorescence spectra of Er3+:I-4(13/2)->I-4(15/2) transition and the lifetime of Er3+:I-4(13/2) level of the samples were measured. The effects of OH- groups on the spectroscopic properties of Er3+ doped samples with the different concentrations were discussed. The results showed that the OH- groups had great influences on the Er3+ lifetime and the fluorescence peak intensity. The OH- group is a main influence factor of fluorescence quenching when the doping concentration of Er2O3 is smaller than 1.0 mol%, but higher after this concentration, the energy transfer of Er3+ ions turns into the main function of the fluorescence quenching. And basically, there is no influence on the other spectroscopic properties (FWHM, absorption spectra, peak stimulated emission cross section, etc.).

Transparent Ni2+-doped MgO-Al2O3-SiO2 glass ceramics with broadband infrared luminescence

We report on transparent Ni2+-doped MgO-Al2O3-SiO2 glass ceramics with broadband infrared luminescence. Ni2+-doped MgO-Al2O3-SiO2 glass is Prepared by using the conventional method. After heat treatment at high temperature, MgAl2O4 crystallites are precipitated, and their average size is about 4.3nm. No luminescence is detected in the as-prepared glass sample, while broadband infrared luminescence centred at around 1315nm with full width at half maximum (FWHM) of about 300nm is observed from the glass ceramics. The observed infrared emission could be attributed to the T-3(2g)(F-3) -> (3)A(2g)(F-3) transition of octahedral Ni2+ ions in the MgAl2O4 crystallites of the transparent glass ceramics. The product of the fluorescence lifetime and the stimulated emission cross section is about 1.6 X 10(-24) s cm(2).

荧光俘获效应对掺铒氧化物玻璃光谱性质的影响

测试了不同掺杂浓度和样品厚度下掺铒磷酸盐和碲酸盐玻璃的吸收光谱、荧光光谱和荧光寿命，计算了Er^3＋离子在1．53μm处的吸收截面（σa）、发射截面（σe）、自发辐射跃迁概率（Arad）、辐射跃迁寿命（τrad）、以及辐射跃迁量子效率（η）等光谱参数．讨论了荧光俘获效应对掺铒磷酸盐和碲酸盐玻璃光谱性质及光谱参数的影响．结果表明即使在铒离子低掺杂浓度（0．1mol％Er2O3）下，荧光俘获效应也普遍存在于掺铒玻璃材料中，使得荧光寿命（τt）和荧光半高宽（FWHM）随样品的厚度和铒离子掺杂浓度增加而增大，导致

Spectroscopic properties and thermal stability of Er3+/Yb3+-codoped fluorophosphate glasses

A comprehensive study on the thermal stability and spectroscopic properties of Er3+/Yb3+-codoped Al(PO3)(3)-based fluorophosphate glasses is reported of the 1.5μ m fibre amplifiers in this paper. From optical absorption spectra, the Judd-Ofelt parameters of Er3+ in the glasses and several important optical properties, such as the radiative transition probability, the branching ratio and the spontaneous emission probability, have been calculated by using Judd-Ofelt theory. The fluorophosphate glass exhibits broadband near-infrared emission at 1.53μ m with a full width at half-maximum over 63nm, and a large calculated stimulated-emission cross-section of 6.85 x 10(-21)cm(2).

Effects of Yb ion concentration on the spectral properties of lead silica glasses

The spectral properties in different concentration of Yb ions (0.5-5 mol%)-doped silica glasses are explored in this paper. The glasses are prepared by traditional melting method. The absorption spectra and the fluorescent lifetime (tau(f)) are measured at room temperature and low temperature (18 K). The stimulated cross-section (sigma(emi)) and potential laser properties (beta(min), I-sat, I-min) are calculated based on the absorption spectra. The absorption cross-section (sigma(abs)) are in the range 1.08 x 10(-20) - 1.18 x 10(-20) cm(2) in different glasses, the fluorescence lifetime (tau(f)) change from 1.9 to 1.2 ms with the increase of Yb3+ concentration. The potential laser properties indicate that lead silica glass is a good host for highly Yb ion doping glass. (c) 2005 Elsevier B.V. All rights reserved.

Effect of F- ions on spectroscopic properties of Yb3+-doped zinc-tellurite glasses

this paper is retracted

Preparation and spectroscopic properties of Yb-doped and Yb-Al-codoped high silica glasses

Yb-doped and Yb-Al-codoped high silica glasses have been prepared by sintering nanoporous glasses. The absorption, fluorescent spectra and fluorescent lifetimes have been measured and the emission cross-section and minimum pump intensities were calculated. Codoping aluminum ions enhanced the fluorescence intensity of Yb-doped high silica glass obviously. The emission cross-sections of Yb-doped and Yb-Al-codoped high silica glasses were 0.65 and 0.82 pm(2), respectively. The results show that Yb-Al-codoped high silica glass has better spectroscopic properties for a laser material. The study of high silica glass doped with ytterbium is helpful for its application in Yb laser systems, especially for high-power and high-repetition lasers. (C) 2007 Elsevier B.V. All rights reserved.

Novel Bi-doped glasses for broadband optical amplification

Broadband infrared luminescence is observed in various Bi-doped oxide glasses prepared by conventional melting-quenching technique. The absorption spectrum of the Bi-doped germanium oxide glass consists of five broad peaks at below 370, 500, 700, 800 and 1000 nm. The fluorescence spectrum exhibits a broad peak at about 1300 nm with full width at half maximum (FWHM) of more than 300 nm when excited by an 808 nm laser diode. The fluorescence lifetime at room temperature decreases with increasing Bi2O3 concentration. Influence of the glass composition and melting atmosphere on the fluorescence lifetime and luminescent intensity is investigated. The mechanism of the broadband infrared luminescence is suggested. The product of stimulated emission cross-section and lifetime of the Bi-doped aluminophosphate glass is about 5.0 X 10(-24) cm(2) s. The glasses might be promising for applications in broadband optical fiber amplifiers and tunable lasers. (c) 2007 Elsevier B.V. All rights reserved.