【作者】 吴铭；

【导师】 黄德修；

【作者基本信息】 华中科技大学 ， 电子科学与技术， 2008， 博士

【摘要】 光子晶体光纤自1996年问世以来得到了迅速发展,理论分析不断完善,制造工艺不断提高,新型光子晶体光纤的设计不断出现,基于光子晶体光纤的应用也不断涌现。目前光子晶体光纤已成为当前世界范围内光电子学领域的研究热点。本文对光子晶体光纤的理论进行了系统、深入的研究;并对光子晶体光纤的制造工艺和关键技术进行了详细研究;对折射率导引光子晶体光纤的各种特性进行了理论分析和实验研究。本文取得的研究成果如下:1.采用矢量光束传输法和矢量有限元法两种精度较高的方法作为研究光子晶体光纤的理论分析工具,在理论上详细地分析了折射率导引光子晶体光纤的色散特性和非线性特性,与实验测得的数据能较好的相符,印证了这两种方法的正确性。2.对光子晶体光纤的制造工艺进行了深入研究,利用武汉长飞光纤光缆有限公司在光纤制造工艺的优势,采用毛细管堆积拉丝工艺制造了多种结构的光子晶体光纤,其中包括无截止单模光子晶体光纤、高双折射光子晶体光纤、高非线性光子晶体光纤、色散补偿光子晶体光纤、色散平坦光子晶体光纤等一系列光子晶体光纤。3.详细分析了光子晶体光纤的损耗特性,针对制造工艺对损耗的影响,对制造工艺提出了降低损耗的改进方法。其中,我们制造的无截止单模光子晶体光纤的损耗在1550nm处可以达到0.4dB/km,这是我们拉制的损耗最低的一种光子晶体光纤。随着制造工艺的不断改进,其损耗将进一步降低。4.理论分析了光子晶体光纤的结构参数对其色散特性的影响。经过理论模拟计算得出了结构参数与色散特性之间的变化关系,在此基础上设计了一种基于折射率导引光子晶体光纤的宽带色散补偿光子晶体光纤,能够对标准单模光纤进行有效的宽带色散补偿。5.详细研究了中心空气孔光子晶体光纤的色散特性,尤其是引入的中心空气孔对光子晶体光纤色散特性的影响。理论模拟计算得出了中心空气孔的变化对色散影响的规律,在此基础上设计了基于该结构的宽带色散补偿光子晶体光纤和超宽色散平坦光子晶体光纤。在理论研究的基础上,拉制了中心空气孔光子晶体光纤。对拉制的这种光纤进行了一系列的测试,其色散补偿特性的实验结果与理论分析的结果能够很好的相符,在1500～1625nm范围内能达到了-440～-480ps/(nm·km)。6.采用中心空气孔光子晶体光纤结构设计了一种超宽色散平坦光子晶体光纤。这种超宽色散平坦光子晶体光纤,在1200～1600nm的带宽内具有很低的色散值,并且具有极其平坦的色散特性。7.详细研究了光子晶体光纤的非线性系数与结构参数之间的变化关系,为实际的高非线性光子晶体光纤拉制提供了理论依据。在理论研究的基础上,拉制了高占空比的高非线性光子晶体光纤,对其特性进行了一系列的测试,获得了比较理想的实验结果。更多还原

【Abstract】 Since the first photonic crystal fiber (PCF) was fabricated in 1996, the technology of PCF is developing rapidly. The theory of PCF is continuously consummating. And the new designs of PCF are continually appearing. The vast improvements of the fabrication process have been obtained in recent years. The applications of PCF are widely studied. Now the PCF has been widely used in advanced front research of fiber optics and optoelectronics.In this dissertation, the transmission properties of PCF are investigated systematically and deeply. The fabrication process of PCF is investigated, while the key technique of PCF fabrication is achieved. The main achievements of this dissertation are as follows:(1) We theoretically analyzed the properties of PCF by the vectorial beam propagation method and vectorial finite element method. Both of these methods are having satisfactory numerical accuracy and computational efficiency. And there is a reasonable agreement between the calculated result and the experimental result.(2) We investigated the fabrication process of PCF and achieved the key technique of PCF fabrication. And we successfully used the stack-and-draw fabrication technique to fabricated a series of PCFs, such as endlessly single mode PCF, high birefringent PCF, highly nonlinear PCF, dispersion compensating PCF, dispersion flattened PCF.(3) The loss property is analysed specifically, then we proposed the improvement to reduce the level of loss. The loss of endlessly single mode PCF our fabricated can reach 0.4dB/km at 1550nm, which is the lowest level of PCF our fabricated.(4) We discussed the dispersion property with pitch, air-filling fraction. Then we designed a broadband dispersion compensating PCF based the index-guiding structure. It can compensate the dispersion of the single mode fiber in C+L band.(5) We proposed a novel PCF with defected-core. The small central defect of air hole can flexibly control the chromatic dispersion properties of this kind of photonic crystal fiber. Then we designed the broadband dispersion compensating PCF and the ultra-low and ultra-flattened dispersion PCF based this PCF index-guiding structure. And we fabricated the broadband dispersion compensating PCF with air-core according to the theoretical studies. The dispersion compensating photonic crystal fiber with air-core we fabricated has broadband large negative chromatic dispersion, and the chromatic dispersion coefficient varies from -440 to -480ps/(nm·km) in the measured wavelength range of 1500-1625nm. The calculated chromatic dispersion curve is well match to the measured result.(6) We simulated the ultra-low and ultra-flattened dispersion properties of photonic crystal fibers with defected-core, and applied to design PCF with ultra-low and ultra-flattened dispersion in the wavelength range of 1200～1600nm.(7) The dependence of nonlinear coefficient with pitch, air-filling fraction, and wavelength is analyzed systematically, that can be provided the theoretical basis to the practice. According to the theoretical analysis, we fabricated the highly nonlinear PCF. And the measured results of the highly nonlinear PCF are suitable to the calculation.更多还原