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51.
研究了Yb2O3浓度对Tm3 /Yb3 共掺氧卤碲酸盐玻璃的上转换发光的影响,分析了上转换发光机理。结果发现,通过980 nm的激光二极管激发,在室温下同时观察到强烈的蓝光(475 nm)和微弱的红光(649 nm),分别是由于Tm3 离子1G4→3H6和1G4→3F4跃迁产生的;上转换机理分析表明,上转换蓝光和红光都是由于双光子吸收过程。随Yb2O3浓度增加,Yb3 离子寿命降低,Yb3 到Tm3 的能量转移效率增加,上转换蓝光和红光强度先增加,在Yb2O3摩尔比为3时达到最大,然后降低。分析认为,Yb3 的浓度猝灭主要是由于3H4(Tm3 )→2F5/2(Yb3 )反向能量转移的结果。结果表明Yb3 敏化Tm3 掺杂氧卤碲酸盐玻璃是一种上转换蓝光激光器的潜在基质材料。 相似文献
52.
The upconversion properties of Tm^3 /Yb3 -codoped lead chloride tellurite glass under 980hm excitation were investigated. The intense blue (476nm) emission and weak red (649 nm) emission corresponding to the ^1G4→4 ^3H6 and ^1G4→^3H4 transitions of Tm^3 ions, respectively, were simultaneously observed at room temperature. The dependence of upconversion intensities on excitation power and the possible upconversion mechanisms are evaluated. The intense blue upconversion luminescence of Tm^3 /Yb^3 -codoped lead chloride tellurite glass can be used as potential host material for the development of blue upconversion optical devices. 相似文献
53.
Er^{3+}- and Er^{3+}/Yb^{3+}-doped lead germanate glasses that are suitable for use in fibre lasers and optical amplifiers as well as optical waveguide devices have been fabricated and characterized. The absorption spectra from near-infrared to visible were obtained and the Judd-Ofelt parameters were determined from the absorption band. Intense and broad 1.53μm infrared fluorescence and visible upconversion luminescence were observed under 976 nm diode laser excitation. For 1.53μm emission band, the full widths at half-maximum are 36, 37, 51 nm for GPE, GPYE and GPFE samples, respectively. For frequency upconversion emission, the intense bands centred at around 524, 545, 657nm are due to the {}^4S_{3/2}+{}^2H_{11/2}→{}^4I_{15/2} and {}^4F_{9/2}→{}^4I_{15/2} transitions of Er^{3+} ions. The quadratic dependence of the green and red emissions on excitation power indicates that the two-photon absorption process occurs under the 976nm excitation. 相似文献
54.
Hybrid titania/ormosil waveguide films have been prepared by sol-gel method at low thermal treatment temperature of 150℃. The influence of processing parameters including the molar ratios of Ti(OBu)_{4}/glycidoxypropyltrimethoxysilane (GLYMO) and H_{2}O/Ti(OBu)_{4} (expressed as R), especially aging of sol, on the refractive index and thickness of film was investigated. The optical properties of films were measured with Scanning Electron Microscope and m-line spectroscopy. The results indicate that the film thickness increases with the aging time of sol, but the variation of refractive index as a function of aging time of sol depends on the relative ratio of GLYMO to Ti-alkoxide. The relation between film thickness and corresponding sol viscosity is linear as the volume of GLYMO is 80% within the range of measured data. 相似文献
55.
Er~(3+)-doped fluoride lanthanum aluminosilicate glasses with compositions of (65-x/2)SiO_2·(25-x/2)Al_2O_3·xAlF_3·9.1La_2O_3·0.6Er_2O_3·0.3Yb_2O_3(x=4, 8, 12, 20, 30) (mol%) were prepared and their glass transition temperatures and spectroscopic properties were investigated.The Ω_2, Ω_4, and Ω_6 intensity parameters of glasses were calculated by Judd-Ofelt theory from absorption curves. It was found that glasses transition temperature and melting temperature decreased with the increase of fluoride content in glass,Ω_2 decreased gradually with the increase of AlF_3 content,but both Ω_4 and Ω_6 did not increase until AlF_3 content increased to 30 mol%.The quantum efficiency of ~4I_(13/2) to ~4I_(15/2) transition of Er~(3+) ions increases with the increase of AlF_3 content in glass.Fluorescent lifetime is longer in glass containing more AlF_3 content. 相似文献
56.
57.
Er^3 -doped strontium-lead-bismuth glasses for developing potential upconversion lasers have been fabricated and characterized. Under 975 nm excitation, intense green and red emissions centred at 525, 546, and 657nm,corresponding to the transitions ^2H11/2 → ^4I15/2, ^4S3/2 → ^4I15/2, and ^4F9/2 → ^4I15/2, respectively, were observed at room temperature. The upconversion mechanisms are discussed based on the energy matching and quadratic dependence on excitation power, and the dominant mechanisms are excited state absorption and energy transfer upconversion for 525 and 546nm emissions, and energy transfer upconversion for 657nm emission. 相似文献
58.
Fluorescence Lifetime Increasing with F- Ions into Ytterbium-Doped Germanium-Lead-Tellurite Glasses 下载免费PDF全文
The effects of F^- ions in a germanium-lead-tellurite glass system on the spectral and potential laser properties of the Yb^3 are investigated. The absorption spectra, lifetimes, the emission cross-sections and the minimum pump intensities of the glass system with and without F^- ions have been measured and calculated. The results show that the fluorescence lifetime and the minimum pump intensity of Yb^3 ions increase evidently, which indicatesthat germanium-lead-oxyfluoride tellurite glass is a promising laser host matrix for high power generation. FT-IRspectra were used to analyse the effect of F^- ions on OH^- groups in this glass system. Analysis demonstrates that addition of fluoride removes the OH^- groups and results in improvement of fluorescence lifetime of Yb^3 . 相似文献
59.
New chemically stable Er_(3+)-Yb_(3+) co-doped phosphate glass for optical waveguide lasers and amplifiers 总被引:3,自引:0,他引:3
A set of phosphate glasses with different amounts of Al2O3, Na2O, La2O3 and AlF3 contents were prepared to search for a phosphate glass which is suitable for ion-exchange process. Based on chemical durability test results and spectroscopic properties, a glass with excellent chemical durability and good spectroscopic properties is developed for ion-exchange process. The emission cross section of Er3+ in this glass is calculated to be 0.72×10~20 cm2 by McCumber theory. The planar waveguide with three modes at 632.8 nm and one mode at 1540 nm can be realized by 335℃ 3 hours ion-exchange in 5%AgNO3+95%KNO3 molten salt. 相似文献
60.
Nd-doped phosphate glass is the dominant amplifier material used in solid state high average power laser systems.Surface imperfection and subsurface damage(SSD)of the glass,resulting from the optical fabrica-tion process,limit the increment of laser system energy output.Thus,it is important to enhance the surface damage threshold of Nd-doped phosphate glass surface.The influence of abrasive size,polishing powder,grinding mode,and chemical treatment on the laser-induced damage threshold(LIDT)of Nd-doped phos-phate glass surface is investigated.Results show that the LIDT is affected little by different polishing powders and grinding modes.The LIDT correlates with the abrasive size,which produced different depths of SSD.A suitable acid etching treatment can remove the imperfection and the SSD for improving the LIDT of Nd-doped phosphate glass surface.The combination of several effective techniques and methods,which are low-cost and practical,should be useful to enhance the LIDT of Nd-doped phosphate glass surface. 相似文献