基于Kerr非线性效应全光逻辑门的研究

发布时间：2019-01-16 01:38

【摘要】：随着人类社会信息化时代的临近,对通信的需求呈现加速增长的趋势。发展迅速的各种新型业务对通信网的带宽和容量提出了更高的要求。在目前的半透明光网络中,电子交换和信息处理网络的发展已接近了极限,为了解决电子瓶颈限制问题,在未来的全光网络中,全光开关将取而代之。全光开关作为实现全光网络的基础器件,在信息技术中有广泛的应用,其中一项重要的应用就是用来构成全光逻辑门,全光逻辑门在光域上能实现各种逻辑操作,是全光计算、全光通信传输系统等关键元器件。由于Kerr非线性效应,非线性耦合器能实现全光开关操作并能构成相应全光逻辑门,近年来备受关注,同时为了降低光开关的偏置功率,基于谐振腔光学双稳性的全光触发开关也逐渐成为研究的热点。因此,本文主要利用了Kerr非线性效应,对基于非线性耦合器交叉相位调制的全光逻辑门和基于谐振腔光学双稳性的全光触发开关进行了研究,具体的工作和主要研究结果如下：首先,我们简要地介绍了非线性光纤耦合器的结构,利用它的耦合模理论,对其开关特性和1所能实现的逻辑门操作进行了分析。同时还概述了微型谐振腔的工作原理,利用耦合器的耦合原理,分别对单耦合器和双耦合器谐振腔进行了分析,通过仿真透射率与相移的关系曲线对各自的开关特性进行了讨论。其次,我们通过合波器向耦合器输入一束强度可调的泵浦光,用交叉相位调制方式引起Kerr非线性效应,进一步对非线性耦合器的开关特性进行了研究。利用耦合模理论,当输入信号光的初始相位相同和不同时,通过仿真透射率与归一化泵浦光的关系曲线,讨论了各自所实现的全光逻辑门。研究指出：当输入信号光的初始相位相同时,我们可以通过改变输入泵浦光的功率,来实现开关功能,当取定一个泵浦光功率时,可以根据输入信号光的不同组合来实现不同的全光逻辑门；当输入信号光的初始相位不同时,可以通过改变输入信号光的相位差,来实现开关功能,当取定一个特定的相位差时,同样可以根据输入信号光的不同组合来实现不同的全光逻辑门。由此可见,我们不仅可以通过改变泵浦光功率来实现全光开关的操作,还可以改变输入信号光的相位差来实现。最后,主要介绍了基于双耦合器谐振腔的全光触发开关,用光学双稳特性产生的Kerr非线性效应,对微型谐振腔的开关特性进行了分析。根据耦合模理论,考虑并分析了失谐量对双稳特性的影响,利用数值法和解析法这两种不同的方法来求解微型腔内的双稳特性曲线,研究结果表明这两种方法得出的结果趋于一致。还分别计算了当考虑和忽略非线性损耗时的双稳情况,当把非线性损耗计算在内时,通过向微型腔中掺杂铒来获得增益,从而来补偿损耗,有效地降低了偏置信号功率。为实现微型谐振腔的触发开关功能,我们在偏置信号上增加了一个设置脉冲信号或重置脉冲信号,而且其信号的持续时间要比腔内电场建立时间要长,根据加入设置脉冲信号和重置脉冲信号之间的时间间隔,可实现谐振腔的开关功能,通过改变时间间隔,还可以得到不同的输出脉冲数字序列。
[Abstract]:With the approaching of the information age of human society, the demand of communication shows the trend of accelerating growth. The rapid development of various new types of services provides for higher requirements for the bandwidth and capacity of the communication network. In the present semi-transparent optical network, the development of the electronic exchange and information processing network has reached the limit, and in order to solve the problem of the limitation of the electronic bottleneck, the full-optical switch will be replaced in the future full-optical network. the full-light switch is used as the basic device for realizing the full-optical network, and has wide application in the information technology, one of the important applications is to form a full-optical logic gate, and other key components such as a full optical communication transmission system. Because of the non-linear effect of the Kerr effect, the non-linear coupler can realize the full-light switch operation and can form the corresponding full-light logic gate. In recent years, attention has been paid, and in order to reduce the bias power of the optical switch, the full-light trigger switch based on the optical double-stability of the resonant cavity has become the hot spot of the research. Therefore, this paper mainly uses the Kerr nonlinear effect, and studies the full-light logic gate based on the cross-phase modulation of the nonlinear coupler and the full-light trigger switch based on the optical double-stability of the resonant cavity. The specific work and main research results are as follows: First, In this paper, the structure of the nonlinear optical fiber coupler is briefly introduced, and the switch characteristics and the logic gate operation which can be realized by using the coupling mode theory are analyzed. At the same time, the working principle of the micro-resonant cavity is also summarized, and the coupling principle of the coupler is used to analyze the single-coupler and the double-coupler resonant cavity respectively, and the characteristic of the switch is discussed by the relation curve of the simulation transmittance and the phase shift. Secondly, a beam of pump light with adjustable intensity is input to the coupler by a wave-in-wave device, and the nonlinear effect of Kerr is caused by the cross-phase modulation method, and the switching characteristic of the nonlinear coupler is further studied. By using the coupling mode theory, when the initial phase of the input signal light is the same and different, the relationship between the transmittance and the normalized pump light is simulated, and the full-light logic gate realized by each method is discussed. It is pointed out that when the initial phase of the input signal light is the same, the switching function can be realized by changing the power of the input pump light, and when a pump light power is taken, different full-light logic gates can be realized according to different combinations of the input signal light; When the initial phase of the input signal light is different, the switching function can be realized by changing the phase difference of the input signal light. It can be seen that not only the operation of the full-light switch can be realized by changing the pump light power, but also the phase difference of the input signal light can be changed. In the end, the paper mainly introduces the full-light trigger switch based on the double-coupler resonant cavity, and analyzes the switching characteristic of the micro-resonant cavity by the Kerr nonlinear effect generated by the optical double-stability characteristic. Based on the theory of coupled mode, the influence of detuning amount on the stability of the double stability is considered and the two different methods of the numerical method and the analytic method are used to solve the double-stable characteristic curve in the micro-cavity. The results show that the results obtained by the two methods tend to be consistent. when the non-linear loss is taken into account and ignored, the gain is obtained by doping the noise into the micro-cavity when the non-linear loss is calculated, thereby compensating for loss and effectively reducing the power of the bias signal. in order to realize the function of the trigger switch of the micro-resonant cavity, a pulse signal or a reset pulse signal is added to the bias signal, and the duration of the signal is longer than that of the electric field in the cavity, According to the time interval between the addition of the setting pulse signal and the reset pulse signal, the switching function of the resonant cavity can be realized, and different output pulse digital sequences can be obtained by changing the time interval.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN929.1;TN622

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