基于受激布里渊散射的慢光研究

发布时间：2018-05-02 19:44

本文选题：受激布里渊散射 + 慢光　；参考：《北京邮电大学》2014年博士论文

【摘要】：随着光纤的广泛应用,光通信得到了迅速的发展。在朝着通信指标高速宽带演进的过程中,对光信号的处理也逐步探索在光域上完成。目前广泛应用的光通信器件,通过实现光电转换,运用成熟的电信号处理技术来实现。受限于光电转换效率、器件兼容等原因,通信器件也逐步要求光器件,以期达到在光域直接调控光信号,获得整个通信系统性能的提升。在通信信号处理中,路由缓存是非常重要的特性,所以光缓存或光存储的研究应运而生。慢光是诸多光存储方案中较为有前景的技术方案之一。近十年时间,国内外研究组对慢光进行了深入的研究。慢光的物理机制可描述为介质受到强的外加场强产生增益区,此增益区间由于K.K.关系(Kramers-Kronig关系)会产生折射率或相位的急剧变化,由群速度和折射率的关系,可推导群速度减慢从而产生慢光现象。从光场对介质产生增益峰的机制不同,有电磁诱导透明(EIT)、相干布居数震荡(CPO)、耦合共振诱导透明(CRIT)、受激拉曼散射(SRS)、受激布里渊散射(SBS)、光参量放大(OPA)等。由研究介质的不同,有冷凝钠原子、光纤、光子晶体、波导等。由于SBS产生机制阈值较低、室温条件、波长连续可调等特性,被认为是最具有应用前景的方案之一。本论文由此进行了基于SBS的慢光研究,主要在光纤介质上进行。由搭建光纤SBS慢光系统展开,进行相关理论和实验研究。首先理论仿真计算了SBS慢光延迟的极限,并由SBS慢光系统布里渊参数的测量和展宽增益谱的要求开展高精度器件的研究,包括基于SBS的光谱分析和光过滤器。最后探索在较低精度仪器系统下实现SBS慢光延迟及分析其性能,提升应用可行性。本研究关键技术在于运用SBS产生的增益峰,导致折射率激变影响信号光的群速度,即所谓慢光。本论文围绕SBS慢光研究,主要在以下四个方面开展了创新研究工作：1.对SBS慢光系统的延迟极限进行讨论,以此分析SBS慢光的光存储延迟性能。通过使用基于(K.K.关系)的仿真模型,对单个脉冲和BPSK的延迟性能分别进行了计算。在常规SBS慢光系统中约32dB最大增益和500MHz增益带宽情形下,2.5ns宽的单个脉冲的最大延迟为2.3ns(0.9bit),500MHz速率BPSK信号的最大延迟为2. Ins (lbit),它们的延迟带宽积分别为1.2和1.1。2.由SBS慢光系统对参数布里渊增益谱的测量,探索了一种全光的高精度光谱测量方案。信号光谱的分辨率可达1OMHz,抑制比为33.5dB。并测量了实际的子载波复用信号(模拟OFDM信号)的光谱。3.由宽带SBS慢光对增益谱谱形状平坦、抑制比高等要求,结合SBS偏振方法提出了一种全光的高精度滤波器方案。获得了宽带增益谱产生的光滤波特性为谱宽250MHz-1GHz可调；顶部传输抖动为1.5dB；选择性为44dB。4.探索一种方法,在SBS慢光系统上实现较低精度仪器平台的搭建,以有效的降低实验仪器指标要求,提高应用可行性。外差方法的监控部件有效的降低了慢光系统对仪器的指标要求。在波长可调精度为1pm的激光器实现了32ns的延迟。相对延迟0.1bit,时延带宽积0.96,时延增益比：0.80ns/dB.
[Abstract]:With the wide application of optical fiber, optical communication has developed rapidly. In the process of high-speed broadband evolution of the communication index, the processing of optical signal is gradually completed in the optical domain. At present, the widely used optical communication devices are realized by realizing photoelectric conversion and using mature signal processing technology. Efficiency, device compatibility and other reasons, communication devices also gradually require optical devices, in order to achieve direct control of optical signals in the optical domain, and improve the performance of the entire communication system. In communication signal processing, routing caching is a very important feature, so the research of optical caching or optical storage arises at the historic moment.
Slow light is one of the more promising technology schemes in many optical storage schemes. In recent ten years, the research team at home and abroad has studied slow light deeply. The physical mechanism of slow light can be described as the gain zone produced by strong external field intensity, which will produce refractive index or phase due to the K.K. relationship (Kramers-Kronig relationship). From the relationship between group velocity and refractive index, we can deduce group velocity and slow light phenomenon.
The mechanism of generating gain peaks from the light field to medium is different, such as electromagnetic induced transparency (EIT), coherent population number oscillation (CPO), coupled resonance induced transparency (CRIT), stimulated Raman scattering (SRS), stimulated Brillouin scattering (SBS), optical parametric amplification (OPA), etc.. By the different medium, there are sodium condensate, optical fiber, photonic crystal, waveguide and so on. Due to SBS production It is considered to be one of the most promising schemes with low threshold, room temperature and continuous wavelength adjustment.
In this paper, the slow light research based on SBS is carried out mainly in the optical fiber medium. The development of the optical fiber SBS slow light system is carried out to carry out the related theory and experiment. Firstly, the limit of the slow light delay of SBS is simulated and calculated, and the high precision device is carried out by the measurement of the Brillouin parameter of the SBS slow light system and the requirement of the broadening gain spectrum. Research, including spectral analysis based on SBS and light filter. Finally, we explore the SBS slow light delay and analysis of its performance under the lower precision instrument system, and improve the application feasibility. The key technology of this study is to use the gain peak produced by SBS to cause the group velocity of the signal light to affect the refractive index shock, that is, the so-called slow light.
This thesis focuses on the SBS slow light research, mainly in the following four aspects: 1. the delay limit of the SBS slow light system is discussed in order to analyze the delay performance of SBS slow light storage. By using the simulation model based on (K.K.), the delay performance of single pulse and BPSK is calculated respectively. In the conventional SBS In the case of 32dB maximum gain and 500MHz gain bandwidth in the slow light system, the maximum delay of a single pulse for 2.5ns wide is 2.3ns (0.9bit), the maximum delay of the 500MHz rate BPSK signal is 2. Ins (Lbit), and their delay bandwidth product is 1.2 and 1.1.2. is measured by the SBS slow light system for the parameter Brillouin gain spectrum, and a whole light is explored. A high-precision spectral measurement scheme. The resolution of the signal spectrum is up to 1OMHz, the suppression ratio is 33.5dB. and the actual subcarrier multiplexing signal (analog OFDM signal).3. is made by the wideband SBS slow light on the gain spectrum shape and the high suppression ratio. A full optical high precision filter scheme is proposed in combination with the SBS polarization method. The optical filtering characteristics of the broadband gain spectrum are adjustable for the spectrum width 250MHz-1GHz, the top transmission jitter is 1.5dB, and the selective 44dB.4. exploration method is used to build the low precision instrument platform on the SBS slow light system, which can effectively reduce the requirements of the experimental instruments and improve the application feasibility. The monitoring components of the heterodyne method are effective. It reduces the requirement of the slow light system for the instrument. The 32ns is delayed by the laser with a wavelength adjustable precision of 1pm. The relative delay 0.1bit, the time delay bandwidth product 0.96, the time delay gain ratio: 0.80ns/dB.

【学位授予单位】：北京邮电大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.1

【参考文献】