光纤隔离器隔离度偏振敏感性的实验研究

本文采用了 1 80°输入测量的新方法研究了光纤隔离器隔离度随着输入线偏振光偏振方向变化。并对其进行了详细的讨论与分析。研究的结果对于该类光纤隔离器的设计和测试具有一定的参考价值     

TRIZ理论在半导体激光器耦合封装中的应用

目的解决在同轴型半导体激光器与光纤耦合封装过程中,由于隔离器的引入造成的耦合速度慢、生产率低,以及隔离器与激光器的封装设备中电磁铁拾放隔离器的机构在拾取隔离器后难以释放等问题。方法应用TRIZ理论矛盾矩阵解决发明问题中技术冲突的方法,提出将隔离器与激光器预先封装在一起再与光纤耦合的工艺流程。结果设计出了全新的拾放机构,优化后的实验样机将1个带隔离器的同轴型半导体激光器与光纤的耦合封装时间由原来的2 min缩短到了40 s。结论新的工艺流程大大降低了整个器件封装的难度,提高了耦合效率。     

抑制噪声的宽带碲基掺铒光纤放大器性能分析

设计了一个带光隔离器的复合型宽带碲基掺铒光纤放大器（EDTFA），通过对该结构模型下的速率方程和光功率传输方程组的数值模拟，理论研究了EDTFA在插入光隔离器后的性能变化。研究表明，通过插入光隔离器抑制反向传输的放大自发辐射（ASE）噪声，可以有效地改善宽带EDTFA的信号增益和噪声特性。在光纤激活长度240cm、铒掺杂浓度2000ppm和前向泵浦功率200mW下，光隔离器插入在最佳位置处时，1540nm～1600nm波段内16路信道小信号增益分别提高了0.8dB～5．9dB，噪声系数降低了0.2dB～2．2dB。研究结果对于新型宽带EDTFA应用于WDM通信系统中具有理论指导意义。     

磁光玻璃的研究进展

高Verdet常数磁光玻璃在光学隔离器、小型激光器、光纤通信和光纤传感等方面都有重要应用.从磁光效应的基本原理出发,系统地综述了逆磁性和顺磁性玻璃的研究发展状况,详细地分析了影响磁光玻璃Verdet常数的主要因素,探讨了磁光玻璃的发展方向.     

反向泵浦光纤喇曼放大器中双重瑞利散射噪声的抑制

研究了反向泵浦光纤喇曼放大器中泵浦和信号和求解方法，并且分析了双重瑞利散射噪声的特性，提出了在考虑反向喇曼光放大作用时，双重瑞利散射噪声的表达式。给出了在加入光隔离器进行抑制后，双重瑞利散射噪声的计算方法，并进行了模拟分析，得出了放置光隔离器的最佳位置。     

稀土铁石榴石磁光材料及其应用

本文综述了稀土铁石榴石磁光材料及磁光器件研究的最新进展；对最具应用价值的高掺Ｂｉ系列和掺Ｃｅ系列石榴石磁光材料作了介绍；在磁光器件方面选择了最具代表性的磁光隔离器和光纤电流／磁场测试仪加以讨论     

稀土铁石榴石磁光材料及其应用

本文综述了稀土铁石榴石磁光材料及磁光器件研究的最新进展；对最具应用价值的高掺Ｂｉ系列和掺Ｃｅ系列石榴石磁光材料作了介绍，在磁光器件方面选择了最具代表性的磁光隔离器和光纤电渗／磁场测试仪加以讨论。     

光纤陀螺的温度试验与误差补偿

分析了光纤陀螺的温度特性及非线性特性,并在组建光纤陀螺温度试验系统的基础上,进行了全温度范围下的位置试验和角速率试验,研究不同的温度及输入角速率对光纤陀螺输出的影响.根据试验结果,分别建立了光纤陀螺零偏的温度模型以及标度因数的温度和非线性模型,并采用最小二乘法拟合模型的参数.通过实测数据进行仿真验证,结果表明,建立的模型能够较好地描述光纤陀螺的温度及非线性特性,利用该模型进行光纤陀螺的温度和非线性误差补偿,取得了较好的效果,光纤陀螺的测试精度得到了较大程度的提高.     

防爆隔离器在油罐自动计量中的应用

加油站是消防重点单位 ,油罐又是加油站的重点 ,油罐自动计量装置使用的传感器虽都是防爆的 ,但对加油站的管理者来说 ,仍是谈电色变 ,总担心会造成巨大的损失。这就为我们计量工作者提出了一个新的课题 ,需要我们在技术上创新。油罐自动计量仪防爆隔离器就是为满足这一要求研制的。防爆隔离器是根据“帕斯卡定律”设计的 ,其示意图如下 :防爆隔离器示意图１ 腔体 ;２ 观测镜 ;３ 视油器 ;４ 阀门 ;５ 调节阀防爆隔离器由腔体、观测镜、视油器、阀门、调节阀及输入输出管组成。腔体内装有色防冻液 ,油罐通过输入管与腔体连接 ,油进入腔体的…     

宽带碲基掺铒光纤放大器增益谱特性研究

建立了一个多信号共存情形下宽带碲基掺铒光纤放大器(EDTFA)四能级模型,系统研究了EDTFA 增益谱随着光纤激活长度、输入信号功率、泵浦功率和纤芯掺杂浓度的演变关系。研究表明,在输入信号功率减小、泵浦功率提高时,C 波段信号增益迅速增大;在光纤长度增长、掺杂浓度提高时,增益谱向 L 波段偏移;在小信号状态下,其 20dB 增益带宽大于 80nm。研究揭示了EDTFA 适合于作为 WDM 系统中的 L 波段和 C L 波段光纤放大器。     

Concise Experimental Designs

This modest paper contains a much more concise representation of the popular experimental design generators for fractional factorial designs. The information is indexed by the information that the experimenter will start with: the number of factors and the desired resolution for the experiment. Its format facilitates the exploration of the effect of changing the experimental design by using a different number of factors or by changing the experiment resolution.     

Experimental and numerical studies in model composites Part I: Experimental results

Results on strength, apparent toughness, fatigue crack growth and fiber debonding on specially made composite materials are reported. The compact tension composite specimen used consisted of an epoxy matrix and layers of long aligned glass or kevlar fibers that were equally spaced. The experimental data on crack initiation strength showed that for a range of fiber spacing , the composite's strength _A , scaled with the fiber spacing in the form of % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaciaacaqabeaadaqaaqaaaOqaaiabeo8aZnaaBa% aaleaaieGacaWFbbaabeaakmaakaaabaGaeq4UdWgaleqaaOGaeyyp% a0JaeqOUdSgaaa!3EB5!\[\sigma _A \sqrt \lambda = \kappa \]. The apparent toughness of the composite specimens increased with a decrease in fiber spacing. Two sets of fatigue crack propagation experiments were performed. The first one was on specimens with the same fiber spacing and under different applied loads. The second set was on specimens with different fiber diameter and the same loading conditions. While crack arrest was observed in the first set, crack arrest was seen in the second set for the relatively large diameter fibers and specimen fracture for the relatively thin fibers. A method, based on fracture mechanics principles and crack opening displacements, for evaluating bridging tractions is outlined. Using this method, simulations for the bridging tractions and stress intensity factor were carried out using a linear crack opening profile. The total stress intensity factor was found to decrease with crack length. The debonding in the bridging zone, on specimens with different fiber spacing, was evaluated using a one dimensional debonding analysis. The model was calibrated with the debonding on the first fiber and consequently used to describe debonding on the bridging zone of specimens with different fiber spacing. In spite of the assumptions adopted in the present studies, the model seems to describe debonding well.     

Experimental evolution gone wild

Because of their large population sizes and rapid cell division rates, marine microbes have, or can generate, ample variation to fuel evolution over a few weeks or months, and subsequently have the potential to evolve in response to global change. Here we measure evolution in the marine diatom Skeletonema marinoi evolved in a natural plankton community in CO₂-enriched mesocosms deployed in situ. Mesocosm enclosures are typically used to study how the species composition and biogeochemistry of marine communities respond to environmental shifts, but have not been used for experimental evolution to date. Using this approach, we detect a large evolutionary response to CO₂ enrichment in a focal marine diatom, where population growth rate increased by 1.3-fold in high CO₂-evolved lineages. This study opens an exciting new possibility of carrying out in situ evolution experiments to understand how marine microbial communities evolve in response to environmental change.