Effect of OH- content on emission properties in Er3+-doped tellurite glasses

A series of tellurite glasses of composition, 75TeO(2)-20ZnO-(5 - x)La2O3-xEr(2)O(3) (x = 0.05, 0.1, 0.3, 0.6, 1.0, 2.0, and 3.0 mol%) with different hydroxl content were prepared. The effect of Er3+ and OH- groups concentration on the emission properties of Er3+: I-4(13/2) -> I-4(15/2) transition in tellurite glasses was investigated. The constant KOH-Er for Er3+ in tellurite glasses, which represents the strength of interaction between Er3+ and OH- groups in the case of energy migration, was about 14 x 10(-19) cm(4) s(-1). The interaction parameter C-Er,C-Er for the migration rate of Er3+ : 4I(13/2) -> I-4(13/2) transition in tellurite glass was 46 x 10(-40) cm(2), which indicates that concentration quenching in Er3+-doped modified tellurite glass for a given Er3+ concentration is much stronger than in silicate and phosphate glasses. (c) 2007 Elsevier B.V. All rights reserved.

Broadband near-infrared emission in Er3+-Tm3+ codoped chalcohalide glasses

The near-IR emission spectra of Er3+-Tm3+ codoped 70GeS(2)-20In(2)S(3)-10CsI chalcohalide glasses were studied with an 808 nm laser as an excitation source. A broad emission extending from 1.35 to 1.7 mu m with a FWHM of similar to 160 nm was recorded in a 0.1 mol.% Er2S3, 0.5 mol.% Tm2S3 codoped chalcohalide glass. The fluorescence decay curves of glasses were measured by monitoring the emissions of Tm3+ at 1460 nm and Er3+ at 1540 nm, and the lifetimes were obtained from the first-order exponential fit. The luminescence mechanism and the possible energy-transfer processes are discussed with respect to the energy-level diagram of Er3+ and Tm3+ ions. (C) 2008 Optical Society of America

High Er3+ concentration low refractive index fluorophosphate glass for evanescent wave optical amplifiers

This is about the first reported laser glass with very low no, high Er3+ concentration and no quenching. In this work, a series of high Er3+ concentration (10.6-12.2 x 10(20) ions/cm(3)), low refractive index (n(1550) < 1.47) and relatively high fluorescence lifetime (6.8-12.6 ms) fluorophosphate glasses were made. A cw-pumping evanescent wave optical amplifier experiment was performed with it, and a relative gain of around 2dB at 1550 nm wavelength was achieved while the noise level was almost unchanged. To our knowledge, this is the first successful relative gain in evanescent wave optical amplifiers (EWOA) demonstrated with cw pumping. It is a valuable study of specially designed fluorophosphate glass suitable for EWOA communication experiment. (C) 2008 Elsevier B.V. All rights reserved.

碱金属和碱土金属氟化物对掺Er^3＋氟磷酸盐玻璃光谱性质的影响

研究了碱金属和碱土金属离子修饰的掺Er^3＋氟磷酸盐玻璃的光谱性质，讨论了碱金属和碱土金属对铒氟磷玻璃的吸收和发射截面、荧光半高宽，Judd-Ofelt强度参数和上转换发光强度等光谱性质的影响，并与一些传统氧化物玻璃系统进行了比较．研究表明碱金属K^＋和碱土金属Sr^2＋掺杂高的玻璃更适宜用作光放大器基质．含12mol％K^＋的氟磷玻璃展现出7．83×10^-21cm^2的高发射截面和最小的荧光上转换强度；含23mol％Sr^2＋的氟磷玻璃则有7．58×10^-21cm^2的高发射截面、65nm的荧光半高

用于波导放大器的Er^3＋／Yb^3＋共掺磷酸盐玻璃的性能研究

通过优化熔融条件和玻璃组份，成功开发出一种新的Er^3+／Yb^3+共掺磷酸盐玻璃，其在沸水和熔盐中均表现出很好的化学稳定性。通过分析室温下Er^3+／Yb^3+共掺磷酸盐玻璃的吸收光谱，计算得到了Er^3+离子在波长1533nm处的峰值发射截面和杜得-奥菲而特强度参数；其中Er^3+离子在波长1533nm处的峰值发射截面为0．72×10^20cm^2，大于Schott的IOG1玻璃中Er^3+离子的峰值发射截面0．67×10^-20cm^2。通过改变离子交换的条件，获得了1．55μm单模光波导的制作条件

MOCVD growth and properties of ZnO thin films on LiNbO3 substrates

ZnO thin films were grown on (0001)LiNbO3 substrates by the MOCVD technique. The substrate temperatures during growth were changed from 400 to 600 degrees C. The X-ray diffraction (XRD) pattern of the ZnO film showed a strong [002] reflection peak, and the peak intensity was dependent on substrate temperature. The ZnO columnar grains were highly oriented along the (002) direction when the film processing temperature was 600 degrees C. The optical transmission and PL results also indicated that highest crystalline quality of the ZnO films could be obtained at elevated temperatures. (c) 2005 Elsevier B.V. All rights reserved.

Annealing effect on properties of ZnO thin films grown on LiNbO3 substrates by MOCVD

ZnO films were grown on (0 0 0 1) LiNbO3 substrates by metal organic chemical vapor deposition (MOCVD). Annealing of ZnO films was performed in air for I h at 800 degrees C. The effects of annealing on the structural and optical properties of ZnO thin films on LiNbO3 substrates were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM) and photoluminescence (PL) measurements. XRD patterns and AFM showed that the as-grown and the annealed ZnO films grown on LiNbO3 substrates had c-axis preferential orientation, the crystallinity of the ZnO films grown on LiNbO3 Substrates was improved, and the grain size increased by annealing. The PL spectra showed that the intensity of the UV near-band-edge peak was increased after annealing, while the intensity of visible peak (deep-level emission) decreased. (c) 2005 Elsevier B.V. All rights reserved.

Growth and spectral properties of Gd2SiO5 crystal codoped with Er and Yb

Gd2SiO5 (GSO) single crystal codoped with Yb3+ and Er3+ (Abbr. as Er:Yb:GSO) was successfully grown by the Czochralski (CZ) method for the first time and the spectral characteristics were investigated. The absorption and fluorescence spectra were measured. The emission lifetime of the I-4(13/2)-Er-level was measured to be 5.84ms and the emission cross-section at 1529nm was calculated to be 1.03 x 10(-20) cm(2). The results indicate that Er:Yb:GSO is a potential laser material at similar to 1. 55 mu m wavelength region. (c) 2006 Elsevier B.V. All rights reserved.

Co^2＋，Er^3＋：Y3Al5O12晶体的生长及其吸收特性

应用中频感应提拉法成功生长出新型的Co^2＋，Er^3＋：Y3Al5O12晶体。研究了室温下晶体的吸收光谱性能。结合Er^3＋：Y3Al5O12晶体的光谱，并利用调Q判据对Co^2＋，Er^3＋：Y3Al5O12晶体调Q特性进行了简单的分析。结果表明Co^2＋，Er^3＋：YAG晶体是一种很有潜力的白调Q激光晶体。

K2O助溶剂提拉法和富锂提拉法生长的近化学计量比LiNbO3晶体性质的比较

分别采用K2O助溶剂提拉法和富锂提拉法生长了近化学计量比LiNbO3晶体。比较了两种方法生长的晶体紫外吸收边和红外吸收谱的差别，光谱结果表明，K2O助溶剂提拉法生长的晶体组成非常均匀，而富锂提拉法生长的晶体组成不均匀，沿晶体生长方向，Li2O含量逐渐增加。另外，两种生长方法中，籽晶表面均看到螺旋状环，分析了其产生原因。

Er^3＋掺杂钨酸铅晶体的发光和光谱特征

本试验测试了Er^3＋掺杂钨酸铅晶体（PbWO4：Er^3＋）的吸收光谱，依据J-O理论，首次计算报道了光谱项特征：J-O强度参数、量子荧光效率、荧光分支比等，Ω2=3．75×10^-20cm^2，Ω4=0．67×10^-20cm^2，Ω6=0．41×10^-20cm^2。计算证实，PWO：Er^3＋中几乎有80％的激发能量非辐射跃迁转移致^4I13／2能级，^4I13／2的计算寿命是5200μs，J-O计算显示，在PWO中产生^4I13/2→^4I15/2和发射1．53μm．有高的几率。讨论了不同浓度E