共查询到18条相似文献,搜索用时 109 毫秒
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吸收式气敏传感空芯光纤的设计和制备 总被引:3,自引:0,他引:3
研发了红外波段吸收式气敏传感空芯光纤.空芯光纤的内面镀有银膜和介质膜,在目标波长提高反射率从而降低损耗.银膜和介质膜分别采用化学银镜反应法和液相镀膜法成膜.优化介质膜的材料和膜厚.光纤在可见光到中红外波段实现了低损耗特性.空芯光纤不仅可以用作气体传感的光吸收气室,而且也可用作红外光的传输媒介.初步实验结果显示这种空芯光纤可以替代普通的气体吸收气室,实现传感系统小型化. 相似文献
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文章对传输紫外激光空芯光纤系统进行了研究,利用高斯光束传输规律和波导耦合理
论研究了紫外激光与空芯光纤的耦合,分析了在选定毛细管内镀制选定膜系可以制备传输紫外激光的空芯光纤,并针对空芯光纤内径较大而导致的输出光斑较大的问题,提出使空芯光纤输出端与透镜耦合方案。 相似文献
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用集束空芯传能光纤提高激光强度的实验研究 总被引:1,自引:0,他引:1
利用7根多晶态GaO2空芯传能光纤,将7台50W的CO2激光器输出的激光能量合并成一束激光,使输出的激光功率达到319W,聚集后激光光斑直径为0.2mm,由此实现低功率激光器合并成高功率激光。 相似文献
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提出了一种计算多层介质膜空芯光纤损耗谱特性的方法,理论分析了介质—金属膜结构红外空芯光纤的传输损耗特性.将各层膜的厚度、材料色散和表面粗糙度等特性引入理论计算后,根据实测损耗谱估算了每层介质膜厚度.通过比较实测和理论计算损耗谱,调整优化了工艺参数.采用液相镀膜法,制作了在中红外波长带有低损耗特性的Ag/SiO2/AgI/SiO2三层介质膜结构空芯光纤. 相似文献
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为研制10.6μm空芯传能光纤,讨论了银层质量、碘化银层质量对空芯波导传输损耗的影响.介绍了研制波长为10.6 μm的空芯传能光纤的工艺方案及其典型参数.通过液相化学沉积法,在石英基底管内壁成功地生成了优质金属银层和碘化银电介质包层.制作了出具有高透过率的空芯红外波导. 相似文献
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提出一种双包层结构Ge/GeO2介质膜空芯中红外光纤.先采用排布法拉制出包层带有多层空气孔的空芯毛细管,最外层涂有一层硅胶,以加强其机械强度,然后利用化学气相沉积和还原方法在空芯石英毛细管中制备出GeO2-Ge的多层介质反射膜,该膜层提高了Ge/GeO2膜层在短波段的反射效率.经光谱检测分析,该光纤可传输波长为3-12μm,并且中间没有出现大的吸收峰. 相似文献
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Fiber-coupled short Fabry-Perot resonators 总被引:1,自引:0,他引:1
An air-gap Fabry-Perot resonator with plane mirrors between closely spaced fiber ends may yield low throughput because of the poor match between the modes of typical single-mode fibers and the resonant mode in the air-gap cavity. The throughput can be improved by confining the resonant mode by a hollow dielectric tube placed inside the resonator. Short fiber-coupled Fabry-Perot resonators with and without an inserted hollow dielectric waveguide and expressions for their transmission losses are derived. It is shown that the throughput of both types of resonator can be improved significantly by using fiber with large mode size to couple to the resonator. The special fiber is then spliced to a conventional single-mode fiber. It is concluded that the resonator with an inserted hollow dielectric waveguide offers increased throughput for resonators with high finesse 相似文献
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Transmission characteristics of dielectric-coated metallic waveguide for infrared transmission: Slab waveguide model 总被引:2,自引:0,他引:2
A metallic hollow waveguide with inner dielectric multilayers is proposed for the transmission of infrared light and its basic transmission characteristics are fully analyzed by using a two-dimensional slab waveguide model. The power loss in the waveguide is shown to be extremely reduced by coating dielectric layers properly. Simple loss formulas are also presented which consider absorptions of dielectric materials, and minimum possible losses are theoretically estimated. Finally, relations to bending losses in the waveguide are discussed. 相似文献
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《Microwave Theory and Techniques》1971,19(10):834-836
The azimuthally dependent magnetostatic modes have been investigated for two cases: 1) a hollow ferrite pipe is enclosed in a perfectly conducting wall; and 2) a ferrite rod is located at the center of a round waveguide, partially filling the cross section. Our analysis shows that the presence of the dielectric medium has an important role in the determination of the upper bound frequency and the cutoff wave number of the magnetostatic surface modes. 相似文献
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Hollow dielectric waveguides with gas-filled core and a dielectric tube seem promising as laser structures. The tube fulfills the dual role of a guidance structure for the electromagnetic radiation as well as that of a container for the plasma of the gas laser. Feedback for laser oscillation is achieved by providing coupling between forward- and backward-traveling modes by means of periodic ripples of the inner surface of the hollow dielectric tube. This paper is devoted to the derivation of the coupling coefficients between two guided modes that are coupled by ripples in the tube wall. The calculation is based on the model of a slab waveguide. Expressions for the leaky-mode losses and the scattering losses inevitably introduced by the coupling mechanism are also presented. 相似文献
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The problem of a rectangular waveguide open junction is investigated using field theory and the relevant model of two normally intersected, infinite parallel-planes waveguides. Evanescent waveguide modes generated by waveguide wall edges and/or the discontinuity in dielectric are taken into account; an infinite set of equations is derived, where the mode coupling is given by the dielectric slab modes. Proper pole handling is discussed, and a solution for the system is given. Expressions are derived for the reflected, transmitted, and radiated power, which are shown to be sufficiently reliable in the domain of practical interest, regarding the width and the dielectric loading of the gap. The analysis shows that a substantial fraction of the microwave power leaks from the dielectric gap, confirming the absolute necessity of using a choke-flange at the waveguide junction 相似文献
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研究了金属-介质-金属(MDM)型表面等离子体激元(SPP)光波导的电磁特性。理论计算结果表明,对于633nm的TM偏振入射光,当介质膜层厚度小于85nm时,波导中只能激发产生一阶SPP模(基模),其余高阶模全部截止。随着介质膜厚度增加,高阶SPP模逐渐被激发产生。当介质膜层厚度较小时,SPP模的有效折射率的实部随阶数的增加而减小,而虚部则随阶数的增加而增加,SPP基模具有最大传输距离。然而,当MDM波导中的介质层厚度超过0.555μm时,由于三阶SPP模的电磁场主要集中在离金属层相对较远的介质层中,其有效折射率的虚部具有最小值,具有最大的传输距离,而非基模。当入射光波长为633nm介质层厚度为0.9μm时,Ag/SiO2/Ag光波导中三阶SPP模的传输距离达到约150μm。 相似文献