碲酸盐玻璃析晶性能研究

碲酸盐玻璃由于独特的光学性质在光通讯领域具有潜在的应用价值，如掺铒光纤放大器和非线性光学器件，因而得到广泛的关注。近几年，国内外为了提高碲酸盐玻璃的机械性质和光学性能而采取了玻璃的微晶化处理，希望得到碲酸盐玻璃陶瓷。对几种碲酸盐玻璃系统进行了热力学分析，研究比较了其析晶性能，并结合已见报道的文献论证了有望做出玻璃陶瓷的碲酸盐玻璃系统。     

玻璃光学碱度与三阶非线性光学极化率

介绍了玻璃光学碱度的概念,讨论了玻璃光学碱度与三阶非线性光学极化率之间的变化规律,分析了二元硼酸盐、硅酸盐、锗酸盐、碲酸盐、钛酸盐玻璃系统中光学碱度与三阶非线性光学极化率之间变化的定性趋势和定量方程,总结了玻璃光学碱度的本质及其影响,对进一步研究不同玻璃系统中光学碱度与三阶非线性光学极化率之间定量关系的趋势进行了展望.     

AgCl纳米晶掺杂铌碲酸盐系统非线性光学玻璃材料研究

铌碲酸盐非线性光学玻璃具有优良的三阶非线性光学效应,引入适量纳米晶体后,有望进一步提高玻璃的三阶非线性光学性能.本文采用在辅助电场诱导下的热处理方法在TeO2-Nb2O5-BaO-AgCl系统玻璃中析出AgCl纳米晶体,并研究了AgCl含量、热处理工艺及电场施加工艺对纳米晶析出和三阶非线性光学性能的影响.结果发现,在铌碲酸盐系统玻璃中引入0.1%～0.35%(质量分数)的AgCl,经热处理后可在玻璃中获得AgCl纳米晶体,而辅助电场提供的较小推动力可诱导更多的纳米晶体均匀析出,并且可以将其尺寸控制在20nm以下.采用辅助电场与热处理工艺相匹配的控制技术可以明显提高材料的三阶非线性光学性能.     

稀土掺杂碲铌锌系统玻璃的非线性光学性能

碲铌锌系统玻璃是一种性能优良的三阶非线性光学玻璃材料,综合品质优于其它非线性光学玻璃材料。在碲铌锌系统玻璃中引入稀土离子,利用其4f电子的跃迁提高谐波光子激发的可能性,从而提高玻璃的三阶光学非线性。研究表明,随着稀土离子的加入,532nm附近玻璃的光吸收明显增加,使由相同波长激光激发的光学非线性呈线性增长。掺入Ce3+、Ho3+、Y3+的玻璃三阶非线性极化率最高可达2.3×10-12esu。     

TeO2-Nb2O5系统玻璃的成玻性能研究

TeO2是一种线性和非线性光学性能优良、但无法单独形成玻璃的重金属氧化物玻璃系统,Nb2O5的引入有利于获得均匀而稳定的碲酸盐系统玻璃.研究发现,Nb2O5的引入会改变TeO2-Nb2O5系统玻璃中Te4 、Nb5 的配位数,进而对玻璃的结构和成玻能力、稳定性以及析晶性能均产生明显的影响.含有20-30wt%Nb2O5的碲酸盐系统玻璃表现出较好的综合品质.     

1.55μm光纤放大器用掺Er3+碲酸盐玻璃光谱性能研究

制备了TeO2-BaO(Li2O,Na2O)-La2O3掺铒碲酸盐玻璃系统,测量玻璃的密度、折射率和DSC曲线,以及玻璃的吸收光谱和荧光光谱.由测得的密度和折射率等参数,应用Judd-Ofelt理论和McCumber理论,计算出碲酸盐玻璃的各光学性能参数与受激发射截面.且从测得热稳定性能较好的TBLE3荧光发射谱图中得到该碲酸盐玻璃荧光半高宽(FWHM)为～60nm,σepeak×FHWM值高达～600,明显大于掺铒硅酸盐玻璃和磷酸盐玻璃,表明该种碲酸盐玻璃是光纤发大器用的理想基质材料.     

ZnO对碲铌基重金属氧化物玻璃的结构和光学性能的影响

TeO2 Nb2O5系统重金属氧化物玻璃是一种新型的重金属氧化物玻璃材料,具有优良的非线性光学性能。本文研究了ZnO对碲铌基玻璃的结构、非线性光学性能和光学透过率的影响,研究表明:碲铌基玻璃的非线性光学效应源于电子云畸变效应,掺杂少量ZnO有利于玻璃非线性光学性能的提高,增加ZnO至2.5%(质量分数)时用四波混频法测得的玻璃三阶非线性极化率χ(3)可达9.2×10-13esu,然后随ZnO含量增至10%(质量分数)时χ(3)减至6.0×10-13esu。ZnO含量在10%～15%(质量分数)时χ(3)则无明显变化。同时,加入15%(质量分数)的ZnO有利于玻璃透过率的提高。Raman光谱研究表明,掺入过多的ZnO(>5%(质量分数))时,网络间隙中的Nb5+可被Zn2+取代而进入网络,同时提供更多的桥氧,从而使玻璃网络中的[TeO4]4-基团向[TeO3]2-转化。     

TeO_2-Nb_2O_5-BaO-BaCl_2系统玻璃结构及银纳米晶引入研究

碲酸盐氧卤玻璃具有低声子能以及较好的稳定性和析晶性能等优秀的综合品质,是一类很有前途的光学玻璃材料。采用熔融法制备了不同组成的TeO2-Nb2O5-BaO-BaCl2系统玻璃,研究了网络结构变化和组成对该系统玻璃的成玻璃性能和析晶性能的影响,同时探讨了向玻璃基体内引入银纳米晶体的可能性。结果表明,BaCl2的引入使得玻璃网络结构中键合及基团种类增多,碲氧链间的连接加强,网络结构更加紧密,并且成玻璃区域有所扩展。TeO2-Nb2O5-BaO-BaCl2系统玻璃基体在保持自身结构稳定性的同时,更有利于AgCl纳米晶体析出,是一种适合金属纳米晶掺杂的优良光学玻璃基体材料。     

上转换亚碲酸盐光纤激光器研究进展

亚碲酸盐玻璃由于具有较低的声子能量,加上其优良的化学稳定性、热稳定性和机械强度及其光学性能,其可作为光纤放大器和上转换光纤激光器的较理想的基质材料。文章介绍了上转换激光器的主要原理,并回顾了亚碲酸盐玻璃上转换激光器的研究进展。     

宽带放大器用碲酸盐玻璃研究进展

硫酸盐玻璃作为宽带放大器用掺解或掺铥基质材料目前已成为宽带玻璃主动光纤研究的重要组成部分。本文主要从碲酸盐玻璃组成、结构、热稳定性、光谱特性四个方面总结了碲酸盐玻璃研究进展,并对其发展趋势进行了评述。     

Preparation of AgCl Nano-Crystal Embedded Tellurite Nonlinear Optical Glasses under Electric Field Accompanied Heat Treatment

The quantum effect of nano-crystals is an important factor to improve nonlinear optical performance of nanocrystal embedded glasses, while controlling the size distribution and content of nano-crystals in the glass accurately is a key to obtain good quality. The auxiliary direct current electric field, accompanied with heat treatment, was applied on AgCI containing niobic tellurite glass sheet. The nucleation and crystallization of the glass were well controlled under auxiliary electric field. It was found that the average size of AgCI nano-crystal particles in the glass is smaller than that under single heat treatment, and the content of nano- crystals is higher. Therefore the third-order nonlinear optical performance of the glass was increased a lot. The local-area distributed AgCl nano-crystal particles can also be embedded into a glass sheet by using locally applied electric field.     

三阶非线性光学玻璃研究进展

简要叙述了三阶非线性光学理论，重点介绍了近年来国内外三阶非线性光学玻璃领域的研究进展，展望了玻璃作为光信号处理用元件（如全光开关）的应用潜能。     

CsCl Effected Ultrafast Third-order Optical Nonlinearities of GeS_2-Sb_2S_3 Chalcogenide Glasses

A series of alkali halide doped chalcohalide glasses (100?x)(0.9GeS2-0.1Sb2S3)-xCsCl (x=5, 10, 15 and 20 mole fraction) were prepared. The absorption spectra and Raman scatting spectra of these glasses were measured. The optical band gaps Eopt were obtained from ultraviolet absorption edges. Z-scan technique was utilized to investigate the third-order nonlinear optical properties of GeS2-Sb2S3-CsCl glasses. The value of Eopt increases and the third-order optical nonlinearity decreases with increasing CsCl c...     

Optical nonlinearity in photonic glasses

A brief review on optical nonlinearity in photonic glasses is given. For the third-order, relationship between two-photon absorption and nonlinear refractive-index is considered using a formalism developed for crystalline semiconductors. Stimulated light scattering and super-continuum generation in optical fibers are also introduced. Prominent resonant-type nonlinearity in particle-embedded glasses is described. For the second-order, a variety of poling methods are summarized. Finally, it is pointed out that different photoinduced changes can appear when excited by linear and nonlinear optical processes, and the feature is related with glass structures.     

Rare-earth ion doped TeO2 and GeO2 glasses as laser materials

Germanium oxide (GeO₂) and tellurium oxide (TeO₂) based glasses are classed as the heavy metal oxide glasses, with phonon energies ranging between 740 cm^?1 and 880 cm^?1. These two types of glasses exhibit unique combinations of optical and spectroscopic properties, together with their attractive environmental resistance and mechanical properties. Engineering such a combination of structural, optical and spectroscopic properties is only feasible as a result of structural variability in these two types of glasses, since more than one structural units (TeO₄ bi-pyramid, TeO₃ trigonal pyramid, and TeO_3+δ polyhedra) in tellurite and (GeO₄ tetrahedron, GeO₃ octahedron) in GeO₂ based glasses may exist, depending on composition. The presence of multiple structural moities creates a range of dipole environments which is ideal for engineering broad spectral bandwidth rare-earth ion doped photonic device materials, suitable for laser and amplifier devices. Tellurite glasses were discovered in 1952, but remained virtually unknown to materials and device engineers until 1994 when unusual spectroscopic, nonlinear and dispersion properties of alkali and alkaline earth modified tellurite glasses and fibres were reported. Detailed spectroscopic analysis of Pr³⁺, Nd³⁺, Er³⁺, and Tm³⁺ doped tellurite glasses revealed its potential for laser and amplifier devices for optical communication wavelengths. This review summarises the thermal and viscosity properties of tellurite and germanate glasses for fibre fabrication and compares the linear loss for near and mid-IR device engineering. The aspects of glass preform fabrication for fibre engineering is discussed by emphasising the raw materials processing with casting of preforms and fibre fabrication. The spectroscopic properties of tellurite and germanate glasses have been analysed with special emphasis on oscillator strength and radiative rate characteristics for visible, near IR and mid-IR emission. The review also compares the latest results in the engineering of lasers and amplifiers, based on fibres for optical communication and mid-IR. The achievements in the areas of near-IR waveguide and mid-IR bulk glass, fibre, and waveguide lasers are discussed. The latest landmark results in mode-locked 2 μm bulk glass lasers sets the precedence for engineering nonlinear and other laser devices for accessing the inaccessible parts of the mid-IR spectrum and discovering new applications for the future.     

Some studies of the optical properties of tungsten-calcium-tellurite glasses

A range of tungsten tellurite glasses containing calcium was prepared and the densities, optical absorption edges and infrared optical absorption spectra were measured. The optical energy gap is of order 3 eV, somewhat lower than for many oxide-based glasses. It is established that the main absorption bands are related to the bonds in TeO₂ rather than the other components of the glasses.