七芯光子晶体光纤的特性研究

发布时间：2018-02-28 12:13

本文关键词： 全矢量有限元法七芯光子晶体光纤模场面积限制损耗色散　出处：《重庆大学》2015年硕士论文　论文类型：学位论文

【摘要】：光子晶体光纤是光子晶体和传统光纤完美结合的产物,它是通过在由二氧化硅和周期性排列的空气孔构成的二维光子晶体结构中引入线缺陷形成的。随着光子晶体光纤技术的快速发展,光子晶体光纤凭借其独特的包层结构和奇异的光学特性逐步成为光通信领域的研究热点之一。光子晶体光纤根据纤芯的数目可以分为两类:单芯光子晶体光纤和多芯光子晶体光纤。与单芯光子晶体光纤相比,多芯光子晶体光纤具有更大的模场面积、更高的传输容量和的独特的耦合特性,因此多芯光子晶体光纤在高功率光纤激光器、光纤耦合器和光通信系统具有广阔的应用前景。本文以七芯光子晶体光纤作为研究对象,进行了以下几方面的研究:本文研究分析七芯光子晶体光纤的超模分布,并根据其超模分布的特征推导出七芯光子晶体光纤任意两超模的模间色散求解公式。通过在纤芯掺杂低折射率物质的方法改变其超模之间的耦合特性,从而实现七芯光子晶体光纤在1.31μm和1.55μm传输波长处任意两超模之间的零模间色散,并运用全矢量有限元法分析纤芯折射率、纤芯之间的空气孔的位置和包层空气孔大小的变化对零模间色散波长的影响。本文通过在七芯光子晶体光纤的纤芯不同环形区域掺杂高折射率物质,设计一种大模场面积七芯光子晶体光纤。这种光子晶体光纤具有较小的功率峰值和较大的模场面积,其模场面积最大值为3732μm2,与其它结构进行比较后发现:本文所设计的七芯PCF模场面积大于其它结构PCF的模场面积;当本文所设计的这种七芯PCF模场面积达到最大值时,其限制损耗为5.66?10-9d B/m,其它结构PCF获得最大模场面积时其限制损耗为0.06d B/m,由此可知本文设计的大模场面积七芯PCF能同时实现大模场面积和低限制损耗。可以预计,当这种大模场面积的七芯光子晶体光纤作为高功率光纤激光器的基质光纤时,能有效提高激光器的热损伤阈值,降低激光器的非线性效应,实现高功率光纤激光器高功率、高光束质量的激光输出。
[Abstract]:Photonic crystal fiber is the product of perfect combination of photonic crystal and traditional fiber. It is formed by introducing linear defects into two-dimensional photonic crystal structures composed of silica and periodically arranged air holes. With the rapid development of photonic crystal fiber technology, Photonic crystal fiber (PCF) has become one of the hotspots in the field of optical communication by virtue of its unique cladding structure and singular optical properties. PCF can be divided into two categories according to the number of cores: single core photonic crystal fiber and single-core photonic crystal fiber. Multi-core photonic crystal fibers. Compared with single-core photonic crystal fibers, Multi-core photonic crystal fiber has larger mode field area, higher transmission capacity and unique coupling characteristics, so multi-core photonic crystal fiber in high-power fiber lasers, Optical fiber couplers and optical communication systems have broad application prospects. In this paper, seven core photonic crystal fibers are taken as the research object, and the following aspects are studied: in this paper, the supermode distribution of seven core photonic crystal fibers is studied and analyzed. According to the characteristics of supermode distribution, a formula for solving the dispersion of arbitrary two supermodes in a seven-core photonic crystal fiber is derived. The coupling characteristics between supermodes are changed by doping low refractive index material in the core. Thus, the zero-mode dispersion between two supermodes at 1.31 渭 m and 1.55 渭 m transmission wavelength is realized, and the refractive index of the core is analyzed by the full vector finite element method. The influence of the position of the air hole between the core and the size of the cladding air hole on the dispersion wavelength between zero modes is studied. In this paper, high refractive index materials are doped in different annular regions of the core of the seven-core photonic crystal fiber. A seven-core photonic crystal fiber with large mode field area is designed. This photonic crystal fiber has smaller peak power and larger mode field area. The maximum of the mode field area is 3732 渭 m ~ 2. Compared with other structures, it is found that the designed seven-core PCF mode field area is larger than that of the other structure PCF mode field area, and when the designed seven-core PCF mode field area reaches the maximum value, Its limit loss is 5.66? The limiting loss of the other PCF is 0.06 dB / m when the maximum mode field area is obtained by 10-9 dB / m. It can be concluded that the seven-core PCF designed in this paper can realize both the large mode field area and the low limiting loss at the same time. When the seven-core photonic crystal fiber with large mode field area is used as the matrix fiber of the high power fiber laser, the thermal damage threshold of the laser can be increased effectively, the nonlinear effect of the laser can be reduced, and the high power of the high power fiber laser can be realized. High beam quality laser output.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN253

【相似文献】