磁光晶体球型光纤光隔离器

探讨了一种磁光晶体球型光纤隔离器,用ＹＩＧ来研制器件的实验结构,其插入损耗,隔离度和反向损耗的测量结果分别优于８．９ｄＢ,２８ｄＢ和４５ｄＢ理论分析表明,这类器件的有效长度可达０．５ｍｍ以下,插入损耗低于１ｄＢ。     

布拉格光栅辅助型上下话路滤波器的实验制作

采用波长为248nm的紫外光,在由标准单模光纤和自制的高掺锗光敏光纤熔融拉锥制作的2×2光纤失配耦合器上写入光纤光栅,实现了全光纤布拉格光栅(FBG)辅助失配耦合器型上下话路滤波器,并测试了器件的传输特性,器件的插入损耗和回波损耗分别为6.74dB和-18.84dB。用10Gbps的光信号进行了传输实验,分别测试了下话路前、后信号的眼图。与输入信号相比,下话路信号的信噪比从10.04dB降低到了9.27dB,信号的消光比从8.89dB降低到了4.68dB。     

CALCULATION OF INFRARED OPTICAL CONSTANTS FOR CO_2 LASER HOLLOW WAVEGUIDE MATERIALS

A simple method was deduced for calculat-ing Optical constant,optical loss and transmittance per meterOf hollow-core optical fiber using data analysis method,ge-ometerical optical and electromagnetic theory.The methodwas used to study the Na_2O-ZnO-GeO_2-SiO_2-PbO and Sb_3O_3sysem.The glasses have n_r<1 region.When the core diametera_0 is 0.5mm,the hollow waveguides of the Sb_2O_3-containing.glass is predicted with minimum loss of 0.8 dB/m at940cm~(-1).     

光纤连接器端面抛光计算分析

利用ANSYS软件对光纤连接器抛光时端面接触压强分布进行计算分析,通过实验研究证明计算是正确的,从而为光纤连接器端面抛光的优化分析提供充分的理论依据.     

Structure analysis of optical fiber coupler with infrared spectrometry

To obtain excellent performance optical fiber couplers, the structural difference of SiO2 in couplers with different manufacturing techniques was investigated. With 740-FT-IR infrared spectrometric analyzer, the infrared absorption spectrum of SiO2 in couplers at different drawing velocities was measured, and two characteristic peaks in the wavenumber range of 650 - 2000 cm^-1 were observed. One characteristic peak is at about 943 cm^-1 , which is attributed to Si--O Si bond asymmetric stretching vibration, the other is at about 773 cm^-1 , which is attributed to Si--O--Si bond symmetric stretching vibration. From the infrared spectrum, it is found that the intensity and wavenumber of the characteristic peaks are related to the manufacturing technique of couplers. The characteristic peak atabout 943 cm^-1 becomes steeper when increasing the drawing velocity. At the drawing velocity of 150μm/s, the distance between the two characteristic peaks is maximum, and then the optical fiber coupler has excellent performance, indicating that the performance of the optical fiber coupler has a close relationship with the wavenumber of the two characteristic peaks.     

玻璃基集成光功分器的制备与性能表征

针对光纤通信网络的应用,采用Ag+-Na+两步离子交换技术在玻璃基片上制作Y分支级联型1×8集成光功分器,对器件的插入损耗、波长敏感性等关键性能指标进行测试,并对封装好的功分器进行老化实验.研究结果表明,器件的插入损耗典型值为10.3 dB,插入损耗均匀性典型值为0.67 dB;在1 260～1 650 nm波长范围内插入损耗对波长不敏感;在器件老化前后插入损耗变化小于0.1 dB.这些关键性能指标达到Bellcore GR-1209规定的应用标准,与市场上现有的光纤熔融拉锥型光功分器和二氧化硅基集成光功分器的性能指标相当.     

Study on optical constants inversion and infrared transmission characteristics of aerosol particles

Based on the experimental infrared spectral transmittances,an inverse model has been developed to determine the optical constants of the aerosol particles (SiO2 and Al2O3).Combined with the Mie theory and Kramers-Kronig (K-K) relations,the complex refractive indices of the SiO2 and Al2O3 particles are retrieved.The effects of the measurement errors on the inverse results are also investigated.With the optical constants inversed from the experiment,the discrete ordinate method (DOM) is used to calculate the infrared transmission characteristics of the aerosol particle cloud.Considering the multi-scattering and self-emission of the particles,the equivalent transmittance ratio (ETR) is suggested to evaluate the infrared transmission characteristics of the aerosol particles.Particular attention is given to analyze the effects of the volume fraction and diameters on infrared transmission characteristics.When the volume fraction is larger than 0.001,the particle diameter has little effect on the infrared transmission characteristics.For the uniform monodisperse particles in the detection waveband range of 3-5 μm and 8-12 μm,there exists a critical diameter where the ETR reaches the minimum value.In addition,the ETR of 3-5 μm is smaller than that of 8-12 μm with the same volume fraction and particle diameter.     

星用光纤辐射性能实验研究

为了考察商用光纤用于空间星内光总线的可行性,采用辐射剂量率为15.11Gy/min的Co60辐射源对Corning SMF-28和Alcatel 6900进行了在线和离线实验.实验结果表明,在在线观测中,随着辐射剂量的增大,Alcatel光纤比Corning光纤损耗增加快.在辐射剂量达到800Gy时,Corning的感生损耗的增加呈现饱和趋势,而Alcatel光纤仍几乎呈线性增加.离线后,随着时间的推移Corning光纤的感生损耗在逐渐减小,且趋于稳定.Alcatel光纤呈现出相反的趋势,但是也趋于稳定.从结果可以看出,商用光纤用于空间星内光总线对系统功率预算影响不大.     

相似材料中光纤传感检测特性分析

为了解决相似材料模拟实验中的变形检测问题，基于光时域反射技术和光纤光栅传感技术，提出了在模拟实验中采用裸露光纤、一定结构光纤及光纤Bragg光栅作为传感器进行变形检测的方法，研究并分析了以上类型光纤传感器在1．2，2m平面应力模型中随着相似材料变形的传输特性．结果表明：裸露光纤不易形成微弯；自制蛇形微弯光纤传感器可以较为准确地捕捉到材料内部的变形和破坏的信息；光纤Bragg光栅可以感知相似材料的应力变化．利用光时域反射技术检测时要采取措施增大岩层垮落过程中的光纤损耗，可进行较大变形测试；利用光纤Bragg光栅时要考虑波长的动态范围，可进行小变形及破坏过程测试．     

双平行马赫-曾德尔调制器的单边带RoF系统

在光纤承载射频(RoF)系统中,传统单边带调制(OSSB+C)产生的光载波分量和光边带分量之间功率差较大,导致接收灵敏度较低．为此提出了一种利用双平行马赫-曾德尔调制器(MZM)产生OSSB+C信号的改进方法．通过调节该MZM调制器的直流偏压,对于任意调制指数,光载波分量和光边带分量之间的功率都能够平衡,得到最优的0dB载边比(CSR)．仿真结果表明,对于小调制指数,接收灵敏度的改善高达7.8dB; 对于其他情况,接收灵敏度改善0.7~1.1dB．另外,还仿真分析了直流偏压漂移对载边比和接收灵敏度的影响．结果显示,如果将偏压漂移控制在5％范围内,则接收灵敏度下降幅度甚小,因而基于所提出方法的RoF系统具有较好的稳定性．     

4×10Gb/s 800 km transmission system on G.652 fiber with dispersion compensation by chirped FBG

In this paper, the dispersion compensation of 4X 10Gb/s 800km G.652 fiber by chirped optical fiber Bragg grating (FBG) was originally implemented. The characteristics of FBG are optimized, so that the ripple coefficient of reflectivity and time delay are less than 0.9dB and 30ps, respectively. When BER is 10~(-10), the power penalties of transmission are 1.36 dB, 0.89 dB, 1.67 dB and 1.32dB.     

Particle erosion of infrared materials

Erosion test of some infrared (IR) optical crystals (Ge,ZnS,MgF2,and quartz) was conducted with a number of different erodents (glass bead,and angular SiC,SiO2,Al2O3 by a homemade gas-blasting erosion tester.The influence of impact angle,impact velocity,erodent,and erosion time on the erosion rate and the effect of erosion on their IR transmittance were studied.The damaged surface morphology was characterized by scanning electron microscopy,and the erosion mechanism was explored.All of the materials show the maximum in wear versus impact angle at 90°,confirming their brittle failure behavior.It is found that the erosion rate is dependent on the erodent velocity by a power law,and it is highly correlated to the hardness of the erodent.The erosion rate-time curves do not show an incubation state,but an accelerated erosion period followed a maximum erosion (steady state).The decrease of IR transmittance is direct proportion to the erosion rate.Although the material loss occurs primarily by brittle process,ductile behavior is clearly an important feature,especially for MgF2 and ZnS.     

工业废弃物粉煤灰基砌块养护方法的对比研究

对比研究了3种养护方法(自然养护、湿法养护和蒸汽养护)对粉煤灰-石膏-石灰砌块抗压强度和物相组成的影响.结果表明,蒸汽养护样品的抗压强度比自然养护和湿法养护样品的抗压强度提高了1倍多,自然养护样品的水化产物以钙铝黄长石(2CaO.Al2O3.SiO2)为主,湿法养护样品的水化产物以钙长石(CaO.Al2O3.2SiO2)为主,而蒸汽养护制品的水化产物则以钙矾石(3CaO.Al2O3.3CaSO4.32H2O)为主;自然养护和湿法养护样品中火山灰反应不完全,仍有无定形的硅质玻璃体漂珠存在,而蒸汽养护制品中火山灰反应彻底,漂珠已完全消失,所形成的胶凝水化产物多以板状胶结状态存在.机理分析指出,蒸汽养护样品具有最高强度的主要原因是粉煤灰化学激发和热激发.     

双折射光纤传输损耗测试方法的研究

本文提出一种新的测试双折射光纤传输损耗方法。给出了测试原理和实验装五。讨论了这种方法的优点，并对二种不同截止波长的双折射光纤测试了传输损耗系数与波长及人射光仿振态的关系。     

高速全自动光纤熔接接续中的振动分析

从振动原理出发,分析了光纤在切割和移动熔接接续过程中的横向及纵向振动问题,同时阐述了振动与光损耗以及与稳定时间的关系,并为今后高速全自动光纤熔接接续提供了必要的理论依据。     

超薄致密选择性分离层聚醚砜中空纤维膜制备及其气体性能

以聚醚砜为膜材料,N-甲基吡咯烷酮（NMP）为溶剂,乙醇（Ethanol）为非溶剂,NMP-Water为芯液,PES：NMP：Ethanol 35：57：8为铸膜液,采用干／湿相转化法制备了超薄致密选择性分离层PES中空纤维膜,讨论了芯液组成、芯液流量、硅橡胶种类、芯和凝胶槽温度对PES-A中空纤维膜结构、气体性能和机械性能的影响．实验结果表明,适宜的纺丝条件如下：凝胶槽温度17℃,芯液组成NMP：Water86：14,芯液流量0．15mL／min．在适宜的纺丝条件下,比较了PES-A和PES-B2种聚醚砜膜材料的O2／N2气体分离性能,PES-B中空纤维膜的O2／N2选择性为6．23,其O2渗透通量为9．65GPU．此外,在凝胶槽温度9～24℃范围内,PES-B中空纤维膜的O2／N2选择性为5．28～6．23,O2渗透通量为9．65-10．3GPU,并且其超薄致密选择性分离层为427-456A．因此,PES-B中空纤维膜更适合应用于气体分离．     

Mineralogical and sink-float studies of Jajarm low-grade bauxite

Jajarm's bauxite deposits are mainly diasporic,and they have a low mass ratio of Al2O3/SiO2. It is necessary to increase the run-of-mine mass ratio before feeding the material to the Bayer process. Chemical analysis indicated that the low-grade bauxite sample from Jajarm contained 43.9wt% Al2O3 and 13.35wt% SiO2, resulting in a mass ratio of 3.29. According to mineralogical studies, the presence of aluminosilicate minerals such as kaolinite, illite, and quartz was the main reason for the decrease of the mas...     

温度和湿态处理对酚醛/玻纤复合材料抗拉强度的影响

为确定新研制的酚醛/玻纤复合材料的抗拉强度是否满足设计及使用要求,研究了酚醛/玻纤复合材料在-55℃、20℃干态/湿态、71℃干态/湿态和93℃干态/湿态的经向拉伸性能,讨论了不同温度以及湿态处理对酚醛/玻纤复合材料拉伸强度的影响规律,利用扫描电子显微镜(SEM)考察了试件断口的显微结构和断裂形态.研究结果表明:随着温度的升高,酚醛/玻纤层合板的抗拉强度总体呈现下降的趋势.干态条件下,20℃状态的抗拉强度比-55℃状态下的降低了129.9MPa,即降低了24.26%;71℃状态下的抗拉强度比20℃状态下降低了50MPa,即降低了12.33%;93℃状态下的抗拉强度比71℃状态下降低了62MPa,即降低了20.33%.湿态条件下,71℃状态下的抗拉强度比20℃状态下降低了72.3MPa,即降低了29.19%;93℃状态下的抗拉强度比71℃状态下降低了72MPa,即降低了26.57%.在同一温度下,湿态状态下试样的抗拉强度比干态状态下的明显降低.20℃状态下,湿态比干态降低了69.67MPa,即降低了17.18%;71℃状态下,湿态比干态降低了117.7MPa,即降低了33.11%;93℃状态下,湿态比干态降低了111.6MPa,即降低了39.41%.     

Dissolution of Al2TiO5 inclusions in CaO-SiO2-Al2O3 slags at 1823 K

Al-Ti-O inclusions always clog submerged nozzles in Ti-bearing Al-killed steel.A typical synthesized Al2TiO5 inclusion was immersed in a CaO-SiO2-Al2O3 molten slag for different durations at 1823 K.The Al2TiO5 dissolution paths and mechanism were revealed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).Decreased amounts of Ti and Al and increased amounts of Si and Ca at the dissolution boundary prove that inclusion dissolution and slag penetration simultaneously occur.SiO2 diffuses or penetrates the inclusion more quickly than CaO,as indicated by the w(CaO)/w(SiO2) value in the reaction region.A liquid product (containing 0.7-1.2w(CaO)/w(SiO2),15wt％-20wt％ Al2O3,and 5wt％ -15wt％ TiO2) forms on the inclusion surface when Al2TiO5 is dissolved in the slag.Al2TiO5 initially dissolves faster than the diffusion rate of the liquid product toward the bulk slag.With increasing reaction time,the boundary reaches its largest distance,the Al2TiO5 dissolution rate equals the liquid product diffusion rate,and the dissolution process remains stable until the inclusion is completely dissolved.     

光纤熔接损耗及测量

本文讨论了光纤熔接损耗的三个方面,包括光纤熔接损耗的影响因素、如何降低熔接损耗以及熔接损耗的测量,对施工人员了解并控制光纤熔接损耗有很好的帮助。