Low Rayleigh scatteringP2O5-F-SiO2 glasses

The Rayleigh scattering and infrared absorption losses of P₂ O₅-F-doped silica glass, which is a candidate material for ultra-low-loss optical fiber, were investigated experimentally. The Rayleigh scattering loss of 8.5 wt.% P₂O₅ and 0.3 wt.% F-doped SiO₂ glass is found to be 0.8 times that of pure silica glass. It is also found that the infrared absorption property of P₂O₅-F-SiO₂ glass is almost the same as that of pure silica glass. The minimum loss for the proposed composition is estimated to be 0.11 dB/km at 1.55 μm wavelength, and 0.21 dB/km at 1.3 μm wavelength     

Prediction of loss minima in infra-red optical fibres

Loss minima in two fluoride glass and chalcogenide glass fibres were calculated. The intrinsic losses are predicted to be 1 × 10?3 dB/km at 3.4 ?m for BaF2-GdF3-ZrF4 glass fibre, 1 × 10?2 dB/km at 2.7 ?m for BaF2-CaF2-YF3-AlF3 glass fibre and 1 × 10?2 dB/km at 4.5 ?m for GeS3 glass fibre.     

掺杂过渡金属氧化物对ZnO-B_2O_3-SiO_2玻璃的改性研究

采用高温熔融和过渡金属氧化物掺杂的方法,制备了掺杂不同过渡金属氧化物(Sb2O3、TiO2、CeO2、MnO2)的ZnO-B2O3-SiO2无铅玻璃。研究了所制玻璃的物理化学性能。结果表明:掺杂过渡金属氧化物后,ZnO-B2O3-SiO2玻璃的结构和封接性能得到较大改善,玻璃的耐水性提高1.5～2.0倍,线膨胀系数从60×10–7/℃降至40×10–7/℃。     

金属外壳封接用双层玻坯的研制

以BH—G/K玻璃为基体,以添加Al2O3粉的DM—308玻璃为表层区研制出与金属外壳封接的双层玻坯。分析了Al2O3粒度及添加量对熟坯致密化和线收缩率的影响。结果表明,表层区使用添加质量分数为20%和30%0.5μm粒径Al2O3粉的DM—308玻璃可以实现熟坯的匹配收缩,用于UP2113—14外壳熔封。电镀后外壳气密性、绝缘电阻均有数量级提高,玻璃沿引线上爬高度只为BH—G/K玻璃的1/3,显著降低外壳盐雾试验后引线根部易锈蚀和引线受力后绝缘子开裂的风险。     

Room-temperature microfluidics packaging using sequential plasma activation process

A sequential plasma activation process consisting of oxygen reactive ion etching (RIE) plasma and nitrogen radical plasma was applied for microfluidics packaging at room temperature. Si/glass and glass/glass wafers were activated by the oxygen RIE plasma followed by nitrogen microwave radicals. Then, the activated wafers were brought into contact in atmospheric pressure air with hand-applied pressure where they remained for 24 h. The wafers were bonded throughout the entire area and the bonding strength of the interface was as strong as the parents bulk wafers without any post-annealing process or wet chemical cleaning steps. Bonding strength considerably increased with the nitrogen radical treatment after oxygen RIE activation prior to bonding. Chemical reliability tests showed that the bonded interfaces of Si/Si could significantly withstand exposure to various microfluidics chemicals. Si/glass and glass/glass cavities formed by the sequential plasma activation process indicated hermetic sealing behavior. SiO/sub x/N/sub y/ was observed in the sequentially plasma-treated glass wafer, and it is attributed to binding of nitrogen with Si and oxygen and the implantation of N/sub 2/ radical in the wafer. High bonding strength observed is attributed to a diffusion of absorbing water onto the wafer surfaces and a reaction between silicon oxynitride layers on the mating wafers. T-shape microfluidic channels were fabricated on glass wafers by bulk micromachining and the sequential plasma-activated bonding process at room temperature.     

Heat Dissipation of Transparent Graphene Defoggers

In spite of recent successful demonstrations of flexible and transparent graphene heaters, the underlying heat‐transfer mechanism is not understood due to the complexity of the heating system. Here, graphene/glass defoggers are fabricated and the dynamic response of the temperature as a function of input electrical power is measured. The graphene/glass defoggers reveal shorter response times than Cr/glass defoggers. Furthermore, the saturated temperature of the graphene/glass defoggers is higher than for Cr/glass defoggers at a given input electrical power. The observed dynamic response to temperature is well‐fitted to the power‐balance model. The response time of graphene/glass defogger is shorter by 44% than that of the Cr/glass defogger. The convective heat‐transfer coefficient of graphene is 12.4 × 10^?4 W cm^?2 °C^?1, similar to that of glass (11.1 × 10^?4 W cm^?2 °C^?1) but smaller than that of chromium (17.1 × 10^?4 W cm^?2 °C^?1). The graphene‐based system reveals the lowest convective heat‐transfer coefficient due to its ideal flat surface compared to its counterparts of carbon nanotubes (CNTs) and reduced graphene oxide (RGO)‐based systems.     

Preparation of SiO2-B2O3 glass forPANDA optical fibre from colloidal sol-gel process

SiO₂-B₂O₃ glass for the PANDA optical fibre is prepared from the colloidal sol-gel process. The preparation of SiO₂-B₂O₃ glass is through the gellation of fumed silica dispersed in water containing boric acid. Two processes to dry the gel are examined, and freeze-drying is selected as the better drying method. The process produces a dried gel without cracks and with a uniform distribution of boron oxide concentration. The dried gel is sintered into glass     

Glass Fibers with Carbon Nanotube Networks as Multifunctional Sensors

A simple approach to deposit multiwalled carbon nanotube (MWNT) networks onto glass fiber surfaces achieving semiconductive MWNT–glass fibers is reported, along with application of fiber/polymer interphases as in‐situ multifunctional sensors. This approach demonstrates for the first time that the techniques of conducting electrical resistance measurements could be applicable to glass fibers for in situ sensing of strain and damage; the techniques were previously limited to conductive and semiconductive materials. The electrical properties of the single MWNT–glass fiber and the “unidirectional” fiber/epoxy composite show linear or nonlinear stress/strain, temperature, and relative humidity dependencies, which are capable of detecting piezoresistive effects as well as the local glass transition temperature. The unidirectional composites containing MWNT–glass fibers exhibit ultrahigh anisotropic electrical properties and an ultralow electrical percolation threshold. Based on this approach, the glass fiber—the most widely used reinforcement in composites globally—along with the surface electrical conductivity of MWNTs will stimulate and realize a broad range of multifunctional applications.     

玻璃粉含量对钡铁氧体厚膜磁性能的影响

采用丝网印刷法制备了钡铁氧体厚膜,系统研究了玻璃粉含量对钡铁氧体厚膜磁性能的影响。结果表明,随着玻璃粉含量的增大,样品的致密度逐渐提高;饱和磁化强度、剩磁和矫顽力均呈现出先增大后减小的趋势;而剩磁比(Mr/Ms)单调上升。当玻璃粉含量增大到质量分数7%时,所制得样品的饱和磁化强度、剩磁和矫顽力均达到最大值,分别为151,76.6,310 kA/m。当玻璃粉含量为质量分数13%时,剩磁比达到0.615。     

Infrared Optical Fibers

A state of the art review of nonsilica based infrared fibers is presented. Two types of fiber materials have been investigated--crystals and glasses. Crystal fiber work appears to be focused on development of short haul CO/sub 2/ laser power delivering lines at 10.6 µm. The maximum delivering power of the CW CO/sub 2/ laser has reached up to about 100 W by the polycrystalline KRS-5 fiber. A number of glass fibers are being developed in fluorides, sulfides and heavy metal oxides. The best optical attenuation of each glass fiber has been respectively reduced to 21 dB/km at 2.55 µm for ZrF/sub 4/-based glass fiber with a core-clad structure, 78 dB/km at 2.4 µm for As-S unclad glass fiber, and 13 dB/km at 2.05 µm (70 dB/km at 2.40 µm) for GeO/sub 2/-Sb/sub 2/O/sub 3/ glass fiber with a core-clad structure. Recent progress of these infrared fibers offers great potential for new wavelength fiber finks operating in the 2-10 µm region which have not been realized by silica-based fiber.     

UV-induced index changes in Undoped Fluoride glass

Undoped fluoride glass slides have been exposed to pulsed 193-nm ultraviolet (UV) irradiation. Their absorption changes have been measured to evaluate UV-induced index changes using Kramers-Kronig relation. A layer-peeling polishing technique was applied to characterize the local UV-induced index change of highly absorbing glass. Index changes up to 1.75/spl times/10/sup -4/ have been evaluated with this method in fluorozirco-aluminate glass. Fluoroaluminate and fluorozirconate glass showed only small index changes of about 2.0/spl times/10/sup -6/ and 2.6/spl times/10/sup -6/ at a wavelength of 1550 nm.     

The effects of glass-substrate’s surface-treatment on the characteristics of N-channel polycrystalline silicon thin film transistors

We have examined the performance and hot-carrier stress reliability of n-channel polycrystalline silicon (poly-Si) thin film transistors (TFTs) on RCA-leached glass. We have found out that the TFT’s performance and reliability are improved by RCA-leaching of the glass when compared to TFTs on bare glass due to the formation of a silica-rich layer on the glass surface by the RCA-leaching. The silica-rich layer acts as a barrier for impurity diffusion from glass as well as it modifies the poly-Si/glass interface which determines the physical structure of the active poly-Si.     

Linear and Nonlinear Optical Properties of Si Nanoparticles/ Er-Ions Doped Optical Fiber

An alumino-germano-silica glass fiber doped with silicon nanoparticles and erbium ions was fabricated using the modified chemical vapor deposition (MCVD) method. Optical properties of the glass fiber were investigated using a Judd-Ofelt analysis. It was found that incorporating silicon nanoparticles with erbium ions did not alter Er-related optical properties of the silica glass fiber. The incorporation of silicon particles in a fiber core caused wide band absorption from 480 nm to 1200 nm. A third order optical nonlinearity of the Si-Er-doped alumino-germano-silica glass fiber was measured to be about 3.8 x 10^-15 m²/W.     

Influence of Ag+-Na+ ion-exchange equilibriumon waveguide index profiles

The Ag⁺-Na⁺ ion-exchange process in a soda-lime silicate glass was studied at 330° as a function of composition of AgNO₃-NaNO₃ melt, mixing condition, and exchange time. The concentration profile of silver in glass was measured by atomic absorption spectroscopy and SEM technique. The surface index change and the index profile were determined from mode index measurement. Ion-exchange was modeled by an ion-diffusion limited process in the glass with an equilibrium chemical reaction at the melt-glass interface. A large value of 75 for the equilibrium constant at low-silver melt concentrations (<10^-2 mole fractions) shows that uptake of silver in glass varies in highly nonlinear fashion with the melt concentration. The results provide boundary conditions necessary for solution of the diffusion equation and design of single-mode waveguides     

L-band Er3+-doped fluorophosphate glass-fibre amplifier

The first L-band EDFA to employ fluorophosphate glass as the host glass material has been realised. The lowest fibre loss yet reported for fluorophosphate glass fibre of 0.7 dB/m is achieved. The amplifier achieved a flat gain with an average value of 21.7 dB in the L-band.     

Effect of population bottlenecking in Pr fiber amplifiers withlow-phonon hosts

The measured spectroscopic properties of Pr³⁺-doped into sulfide and fluoride hosts are used to model the gain efficiency of a 1300-nm Pr-doped fiber amplifier. It is found that excited-state absorption from the long-lived ³H₅ level in Pr³⁺-doped sulfide glass causes a significant degradation in performance, especially at wavelengths shorter than 1320 nm, Pr³⁺ -doped fluoride glass does not suffer significantly from this effect, although the maximum gain is smaller in the fluoride glass     

激光改性硅酸盐玻璃表面局域制备金属铜层

为了实现普通硅酸盐玻璃表面的金属化,利用波长为355nm的脉冲紫外激光刻蚀粗化活化,并结合化学镀,在其表面局域制备出了导电金属铜层。研究了激光加工参量对玻璃表面微观形貌、粗糙度、刻蚀深度的影响规律,并在玻璃表面成功引入了钯元素。结果表明,当第1次紫外激光扫描速率为200mm/s、脉冲频率为100kHz、能量密度为27J/cm2~37J/cm2和填充间距在10μm左右时,玻璃表面可以获得的刻蚀深度在25μm~35μm之间,刻蚀区域的粗糙度R_a在6μm~7μm之间,此时玻璃不会开裂;而第2次激光的能量密度在9J/cm2~11J/cm2之间时（其余参量不变）,钯元素的引入实现了化学镀铜,此时铜层和玻璃之间的平均结合强度可以达到10MPa以上,铜层的体积电阻率可以达到10-6Ω·cm数量级。这是一种具有局域选择性、无需掩模、低成本、高结合强度和良好导电性的玻璃表面金属化工艺。     

Screen-Printable Silver Pastes with Nanosized Glass Frits for Silicon Solar Cells

In this study, silver pastes containing different sizes of glass frits were employed to form the front-side electrodes in order to examine the size effect of the glass frits on the interfacial microstructures between the front-side silver contacts and the n-type silicon emitter layers, which will subsequently affect the electrical performance of silicon solar cells. The interfacial microstructures at the Ag/Si interfaces were investigated by advanced electron microscopy techniques. The transfer length method (TLM) was used to measure the specific contact resistivity of silver electrodes screen-printed on the n-type silicon substrates. The particle size of the glass frits was found to strongly affect the interfacial microstructures and therefore resulted in different specific contact resistivities (ρ _c) of the fabricated silver ohmic contacts. Nanosized glass frits showed excellent etching ability during engineered thermal treatments. The samples made with silver pastes containing microsized glass frits showed a thick residual glass layer at the Ag/Si interface, while the silver paste with nanosized glass frits was found to form an interface with less glass residue, which led to lower resistance after otherwise identical processing.     

硫系玻璃Ge28Sb12Se60薄膜光学非线性增强色散特性

采用真空热蒸发以及退火工艺制备了支持局域表面等离激元的微纳结构薄膜,在此薄膜上蒸镀了硫系玻璃Ge₂₈Sb₁₂Se₆₀薄膜。应用Z-扫描技术,在飞秒激光脉冲激发下研究其光学非线性增强的色散特性,在650 nm和850 nm波段观察到了非线性吸收增强;非线性折射率随着波长的增加由负变正。通过扫描电子显微镜和透过光谱表征和分析了硫系玻璃Ge₂₈Sb₁₂Se₆₀薄膜非线性吸收增强的原理,非线性吸收随着波长的增加由单光子吸收为主逐渐转变为双光子吸收为主;银膜的微纳结构导致硫系玻璃薄膜的共振中心频率发生了偏移。实验制备的用于增强硫系玻璃非线性的微纳结构制作简单,无需复杂光刻工艺,为非线性光子学器件的设计提供了新的思路。     

Design of double-coated optical fibers to minimize mechanical stripforces

This work investigates the optimal design of double-coated optical fibers to minimize the mechanical strip force. As assumed, herein, the stripper consists of two hinged arms and paired blades with a semicircular bore, Analytical results indicate that the strip force is a function of the stripper's bore radius. The stripper's optimal bore radius attempts to make it close to the glass fiber radius. Notably, the stripper does not damage the glass fiber surface during the stripping process. Based on the type of strip force, the stripping process can be divided into two steps. In the first step, a strip force F_t must break the polymeric coatings and allow the crack on the cutting plane to extend to the glass fiber surface. In the second step, a strip force F_a must break the adhesive bond between the glass fiber and primary coating to remove the polymeric coatings away. The strip force F_a is independent of the stripping length. The strip force F_a and the work deemed necessary to strip the polymeric coatings are proportional to the adhesive stress between the glass fiber and primary coating. The shear strength of the primary coating should exceed the adhesive stress between the glass fiber and primary coating; otherwise, the primary coating cannot be stripped completely from the glass fiber surface. The strip force F_a can be minimized by appropriately selecting polymeric coatings and their thicknesses. To minimize such a strip force, the thickness and Young's modulus of the primary coating should be increased. On the other hand, the thickness and Young's modulus of the secondary coating should be decreased