少模掺铒光纤放大器的仿真研究

发布时间：2018-08-13 14:39

【摘要】：随着移动互联网时代的到来,通信系统中的网络流量呈现指数型的增长趋势,并且已经超过光纤通信系统容量的增长速度。与此同时,现有的单模光纤通信系统的传输容量正在逐渐趋近理论极限(非线性香农极限),因此人们迫切需要开发新的信息传输维度,来满足日益增长的网络流量需求。以模分复用和芯分复用为代表的空分复用技术成为目前最具潜力的技术之一。在进行超远距离通讯时,性能高、能耗低的在线光学放大器是必不可少的。由于具有较大的增益带宽和增益倍数,且适于C波段光信号放大,掺铒光纤放大器极大地促进了光纤通信的发展。但是在模分复用系统中,由于信号模式的增多,现有的单模掺铒光纤放大器已经不再适用。当信息在各个模式上进行独立传输时,较大的模间增益差值将会导致信号失真,误码率增加,从而降低系统传输容量并增大系统传输中断概率。因此,在少模掺铒光纤放大器中,模式间的增益均衡成为衡量模分复用放大系统的重要指标。本文从光纤模式理论及少模掺铒光纤放大器理论模型出发,系统研究了少模掺铒光纤放大器的模式增益、噪声及光谱特性。随后,对实现增益均衡的几种方法进行了详细的研究,对通过泵浦结构的调整实现两模式及四模式增益均衡的情形进行分析,并给出了泵浦结构实现增益均衡的方案,为今后通过空间光调制器实现自适应控制的增益均衡等方法奠定了基础;对通过铒离子分布重新构造实现增益均衡进行研究,利用优化算法,给出适用于四模式群组增益均衡的光纤设计,为拉制相应的少模掺铒光纤奠定了理论基础。
[Abstract]:With the advent of the mobile Internet era, the network traffic in the communication system presents an exponential growth trend, and has exceeded the growth rate of the capacity of optical fiber communication system. At the same time, the transmission capacity of the existing single-mode optical fiber communication systems is gradually approaching the theoretical limit (nonlinear Shannon limit), so people urgently need to develop a new dimension of information transmission to meet the increasing demand of network traffic. Space-division multiplexing, represented by module division multiplexing and core division multiplexing, has become one of the most promising technologies. In ultra-long-distance communication, high performance and low energy consumption are essential for on-line optical amplifiers. Erbium-doped fiber amplifiers greatly promote the development of optical fiber communication because of their large gain bandwidth and gain multiple and are suitable for C-band optical signal amplification. However, due to the increasing number of signal modes, the existing single-mode erbium-doped fiber amplifiers are no longer applicable in mode division multiplexing systems. When the information is transmitted independently in each mode, the larger gain difference between modes will lead to signal distortion and increase the bit error rate, thus reducing the transmission capacity of the system and increasing the transmission interruption probability of the system. Therefore, gain equalization between modes is an important index to measure mode division multiplexing amplifier in low-mode erbium-doped fiber amplifiers. Based on the theory of fiber mode and the theoretical model of low mode erbium doped fiber amplifier, the mode gain, noise and spectral characteristics of low mode erbium doped fiber amplifier are studied systematically in this paper. Then, several methods to realize gain equalization are studied in detail. The two-mode and four-mode gain equalization is analyzed by adjusting the pump structure, and the scheme to realize gain equalization is given. It lays a foundation for realizing gain equalization of adaptive control by spatial light modulator in the future, studies the realization of gain equalization by reconstructing erbium ion distribution, and makes use of the optimization algorithm. The fiber design suitable for four-mode group gain equalization is presented, which lays a theoretical foundation for pulling the corresponding low-mode erbium-doped fiber.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN722

【相似文献】