共查询到20条相似文献,搜索用时 93 毫秒
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钒酸钇晶体楔型光隔离器 总被引:5,自引:1,他引:4
介绍了用钒酸钇晶体的与偏振无关的Wedge型光隔离器的基本原理,用琼斯矢量法得到了插入损耗和隔离度的数学表达式,并介绍了隔离器的结构设计.制作的隔离器光纤到光纤的插入损耗为1.04dB,隔离度为42dB,回程损耗为44.3dB,偏振灵敏度≤0.2dB,带宽大于40nm,体积为10×10×40mm3. 相似文献
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全光纤热光型可变光衰减器 总被引:10,自引:0,他引:10
根据光纤包层中的倏逝场机制,将具有热光效应的聚合物材料直接覆盖在侧边抛磨光纤上,进行了全光纤热光型可变光衰减器(VOA)的研究.根据理论分析,确定了在侧边抛磨光纤的抛磨区上覆盖材料的折射率与纤芯中光衰减量之间的关系,为选择适当折射率的热光材料提供依据.设计适当的侧边抛磨区,利用先进的轮式侧边抛磨技术,制备了侧边抛磨光纤,以达到最佳可变光衰减效果.采用螺绕电极和优化封装,制作出性能优良的全光纤热光型可变光衰减器.性能测试表明,器件插入损耗小于0.1 dB,衰减范围为0~80 dB,偏振相关损耗小于0.02 dB,背向反射大于70 dB.该方法制作的全光纤热光型可变光衰减器具有可用电驱动调控、可靠性高等优点. 相似文献
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CO2激光对称烧写长周期光纤光栅的方法研究 总被引:6,自引:0,他引:6
提出了一种利用高频脉冲CO2激光对称烧写长周期光纤光栅(LPEGs)的方法.线聚焦的CO2激光束经过两面交换120°的全反射镜在光纤的周期方向形成了3束对称、等强度的照射,消除了单侧照射写入引起的折射率改变不均匀,使得烧写出的LPEGs的弯曲光谱特性在光纤的角向均匀一致,最大偏振相关损耗(PDL)降低为0.28 dB.此外,该方法制作的LPFGs的通带插入损耗小于0.5 dB,损耗峰3dB带宽小于10 nm. 相似文献
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熔融拉锥型光纤耦合器损耗的实验研究 总被引:4,自引:4,他引:0
结合2×2熔锥型光纤耦合器的制作,实验研究了拉锥速度、耦合长度、火焰位置3个关键制作参数对耦合器的插入损耗和附加损耗影响。当拉锥速度控制在150μm/s时,耦合器的插入损耗和附加损耗可以控制在较低水平;在拉锥长度较短的区间内,插入损耗与拉锥长度基本成线性关系;制作低损耗耦合器,火焰存在最佳高度为5.75 mm。 相似文献
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史云飞 《光纤与电缆及其应用技术》2007,(5):24-26,42
光纤光栅具有插入损耗小,波长选择性好,易于调谐,使用灵活等优点,成为光纤激光器首选谐振器件.为了适应高功率光纤激光器的发展需求,在粗芯光纤上直接刻制光纤光栅用作谐振器件成了新的研究方向.首先对粗芯光纤光栅中的模式耦合进行理论分析,然后在粗芯光纤上制作了光纤光栅.通过试验发现,改变粗芯光纤的模式激发方式可获得不同的光栅光谱. 相似文献
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By means of exact conformal mapping method we have defined character of dependence of squares amounts of angular part of film
element on angled part dimension. We propose relations, approximating obtained dependence. Calculation results and experimental
researches of large-scale models are represented. 相似文献
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Moshrefzadeh R.S. Radcliffe M.D. Lee T.C. Mohapatra S.K. 《Lightwave Technology, Journal of》1992,10(4):420-425
The temperature dependence of refractive index of polymer films was determined for a number of slab waveguides by a grating coupling method. This dependence was examined as a function of parameters such as molecular weight and glass transition temperature of the polymer. Temperature-induced changes in N TE-N TM , N being the effective index, were studied systematically for different slab waveguide compositions. It is shown that with proper device design and choice of polymeric materials, thermal effects can be reduced 相似文献
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The approaches to prepare a uniform and unified scientific terminology of chemical carcinogenesis are presented. The main definitions proposed (carcinogen, initiation, promotion, mutagen, multistage carcinogenesis, anti-carcinogen, cocarcinogen, carcinogenic risk, etc.) are based on the current state of comprehending mechanisms of the action of chemical carcinogens. 相似文献
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The article describes a model representation of radar probing data in form of a mixture of background and target samples, which is the sum of two random variables with very different parameters. For model development we research the behavior of the central moments of the distribution mix without assuming the distribution law form. An example it is described the detection of the signal at the output of compression system of chirp ionosonde. 相似文献
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罗晓羽 《信息技术与标准化》2008,(6):37-39
论述了推进电子行业标准制修订项目计划管理信息化的必要性.并提出了具体措施;详细介绍了电子行业标准制修订项目计划管理数据库的设计思路和实现方法.阐述了对后续工作的几点思考. 相似文献
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对影响镍镀层内应力的因素做了介绍和分析,提出了对收缩应力的一种解释,提供了排除这些因素影响的方法,指出重视镀液的管理是减少各种影响内应力因素的主要办法。 相似文献
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解决IP网QoS问题是目前通信领域的研究热点之一.虽然研究已经取得了一定的进展,但人们对于IP 网QoS本身的含义及相关的问题还有着不同的理解.本文将从IP网QoS的定义入手讨论相关的一些问题以及解决IP网QoS问题所做的各种努力. 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1968,56(6):1024-1032
Assuming that visual responses are due to the action of particles on the membrane of the visual cells, the stochastic variability of the response should be a function of the number of particles producing it. Quantitative predictions can be made with the aid of a model proposed in previous articles. It is found that responses produced in visual cells of Limulus by absorption of a single photon have the stochastic properties which would be expected if the response to one photon were brought about by 25 particles. It is concluded from this that the processes leading to visual responses produce multiplication of particles. The effects of temperature and of metabolic poisons suggest that these processes are of chemical nature. 相似文献