共查询到20条相似文献,搜索用时 21 毫秒
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空心布拉格光纤是具有一维光子晶体(1DPC)包层和空心芯区的新型光子带隙光纤。针对它在CO2激光传输中的应用,设计和制备了传输波段中心波长在10.6μm的空心布拉格光纤样品。利用傅里叶变换红外光谱仪(FTIR)可以观察到光纤样品在10.6μm具有明显的透射峰。使用CO2激光,通过截断法测量得到光纤样品在10.6μm的传输损耗为2.35dB/m。测量了不同弯曲曲率下光纤样品的弯曲损耗,结果表明弯曲损耗系数随曲率的增大而线性增长。在接近光纤输出端处,弯曲半径为10cm的光纤90°弯曲引入的附加损耗约为2dB。实验结果论证了光纤样品的CO2激光低损耗传输特性,展现了空心布拉格光纤在提升CO2激光操作灵活性上的应用潜力。 相似文献
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We demonstrate that higher order bandgaps in all-silica Bragg fibers can have modes with four orders of magnitude lower confinement loss than those using the fundamental bandgap. A scheme for exploiting the higher order gaps for any specific wavelength via a global scaling of the fiber geometry is proposed. This approach provides lower losses than by reducing the confinement loss of the fundamental gap by scaling the core. Using a variety of modeling techniques, we have examined the band structure and guidance of idealized air-core all-silica Bragg fibers. It is demonstrated that the higher order, low loss, bandgaps analyzed here are uniquely accessible to single-material Bragg fibers, and are fundamentally different from the higher order gaps typically associated with depressed-index Bragg fibers such as the ldquoOmniguiderdquo fibers. Further analysis suggests that some of the key features of the guided modes of Bragg fibers can be understood by considering the properties of single hollow-core homogeneous dielectric waveguides (ldquoboreholesrdquo). 相似文献
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《Lightwave Technology, Journal of》2008,26(13):1877-1884
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简要介绍了光子晶体的原理,由此引出光子带隙型光子晶体光纤的概念、结构、导光机理及其制备,着重分析空气导光型光子晶体光纤的传输特性,并用时域有限差分(FDTD)法仿真了三角形结构空气导光型光子晶体的色散特性,最后展望其应用前景. 相似文献
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Bragg gratings in multimode and few-mode optical fibers 总被引:7,自引:0,他引:7
Bragg gratings in optical fibers in multimode propagation are investigated experimentally and theoretically. Bragg gratings formed in optical fibers in multimode propagation show multiple reflection peaks or multiple transmission dips in the reflection or transmission spectra, respectively. For standard graded-index multimode fiber, the number of reflection peaks of a Bragg grating depends on excitation condition of propagating modes. The number of reflection peaks of a Bragg grating at around 1.55 μm is 19 for highly multimode excitation and 3-4 for lower order mode excitation. We analyze the phase-matching conditions of the propagating modes and identify half of the reflection peaks as the reflection to the same mode and the rest as the reflection to the neighboring modes. In dispersion-shifted fiber, a Bragg grating at around 0.8 μm in three-mode propagation shows three reflection peaks in the reflection spectrum. The temperature dependence of each reflection peak is similar to that of a conventional Bragg grating in single-mode fiber. Polarization dependence measured on a Bragg grating in multimode graded-index fiber is negligible. An advantage of Bragg gratings in multimode fiber (MMF) and the applications are discussed 相似文献
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The hollow-core photonic crystal fibers (HC-PCFs) with integrity structure have been fabricated with an improved twice stack-and-draw technique. The transmission spectrum shows that five photonic band-gaps within 450-1100 nm have been obtained.And the green fight transmission in the HC-PCFs has been observed remarkably. 相似文献
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实验证明,空心的空气-石英光子晶体光纤的纤芯可以局域光,并在理论的基础上,得到光子带隙存在的条件,特定的波带受到限制并沿光纤传导;与每一个波带相对应的光子晶体包层中出现一个完全的二维光子带隙,随着空气填充率的增加,光子带隙的相对大小也会随之变大,而且当减小空气孔尺寸时,光子带隙将被抑制。采用透射谱法在红外波段对带隙型光子晶体光纤进行测量,通过比较光纤的透过谱与光源的光谱,确定是否存在光子带隙。 相似文献
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塑性弯曲蓝宝石单晶光纤的光学特性研究 总被引:1,自引:0,他引:1
为满足医用激光传能要求,使用CO2激光对直径分别为550um和750um的两组蓝宝石单晶光纤进行了塑性弯曲,平均弯曲半径为3.0mm,由单个弯曲引起的额外损耗在900nm处小于0.1dB,对脉冲Nd:YAG激光能量传输的损伤阈值高于30MW/cm^2。实验结果表明,塑性弯曲蓝宝石光纤完全可满足医用激光传能的要求,并可减小输出端弯曲光纤头的体积,增大光纤激光传输应用系统的灵活性。 相似文献
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Air-guiding photonic bandgap fibers: spectral properties, macrobending loss, and practical handling 总被引:8,自引:0,他引:8
Hansen T.P. Jes Broeng Jakobsen C. Vienne G. Simonsen H.R. Nielsen M.D. Skovgaard P.M.W. Folkenberg J.R. Bjarklev A. 《Lightwave Technology, Journal of》2004,22(1):11-15
For development of hollow-core transmission fibers, the realizable fibers lengths, bandwidth, characterization, and compatibility with standard technology are important issues. We report record-length air-guiding fiber, spectral properties, splicing, and optical time domain reflectometer (OTDR) measurements. Furthermore, spectral macrobending loss measurements for two different designs of air-core photonic bandgap fibers are presented. While bending loss is observed, it does not limit operation for all practical bending diameters (>5 mm). 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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Niay P. Bernage P. Douay M. Fertein E. Lahoreau F. Bayon J.F. Georges T. Monerie M. Ferdinand P. Rougeault S. Cetier P. 《Photonics Technology Letters, IEEE》1994,6(11):1350-1352
Bragg gratings have been written within four germanosilicate fibers either by a pulsed or by a continuous-wave exposure of each fiber to a coherent UV two-beam interference pattern. These gratings have been exposed under steady state conditions to γ-ray doses as high as 10 4 Grays. The dose rates ranged between 10 Gy/h and 1.3×102 Gy/h. The transmission spectra of the fibers have been recorded during and after the 60Co irradiation, near the grating Bragg wavelengths. Whereas the induced loss reached 600 dB/km near 1.3 μm, no significant change in the spectral characteristics of the gratings could be detected within the experimental accuracy, enabling their future use in a nuclear environment 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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空心光子晶体光纤(PCF)的空气填充率是影响PCF性能的一个重要参数。针对几种不同的空气填充率,设计出了几种不同结构的空心PCF。应用平面波展开法对其进行了研究,分析讨论了空气填充率对特殊结构PCF泄漏模以及色散系数的影响。 相似文献
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We fabricated resonant-cavity light-emitting diodes (LEDs) emitting at 650 nm. Compressively strained GaInP quantum wells were used as an active layer embedded between AlGaAs-AlAs Bragg mirrors. The Bragg mirrors formed a one-wavelength optical resonator. Two devices with different light-emitting areas were compared: 1) a large area chip (300 μm×300 μm) with a conventional LED contact and 2) a small area chip with an 80-μm light opening with an annular contact. Large devices are more suitable for high output power whereas the smaller devices might be useful for data transmission e.g., via plastic optical fibers. For epoxy-encapsulated large area devices, we achieved a maximum wall-plug efficiency of 10.2% and maximum output power of 12.2 mW at 100 mA. The small area LEDs yielded 2.9 mW at 20 mA and a maximum wall-plug efficiency of 9.5% 相似文献
20.
Jacques Lucas 《电信纪事》1986,41(1-2):32-38
This contribution is a review of a new field between material science and optics. Two kinds of materials are used for the fabrication of IR waveguides: glasses and crystalline compounds. Metallic halides mainly fluorides and chalcogenides are the most promising candidats because of their predicted ultralow losses, 10?2, 10?3 dB/km, and their broad transmission range. Special attention is paid to fibers operating in the CO2 laser emission region near 10.6 μm. Fluoride glasses, because of their potential ultratransparency, appear to be the candidates for optical fibers of the second generation operating in the 2–4 μm band. IR optical fibers will find many applications in the field of power and informations transmission as well as in the broad field of censors technology. 相似文献