Atmospheric monitoring for next generation cable free optical communication technologies

无缆光通信系统对于构建未来的通信网络至关重要。传统的无线连接是基于无线电或微波系统。然而，这些系统的容量基本上小于光学系统。根据对英国电信公司网络需求的详细分析，结合空分复用等先进通信技术的自由空间光链路将需要与更传统的光纤分布一起部署，以满足未来5-10年的网络容量需求。空分复用（SDM）是一种通信方案，其中激光束在空间自由度上成形以提供附加的通信信道。SDM被广泛认为是高容量通信的下一个前沿，来自世界各地的研究人员在这一领域非常活跃。在这个项目中，我们将集中在大气湍流的中心问题。这种湍流是由空气中的温度和压力变化引起的，并导致光学模式在大气中传播时的位置、相位和形状发生变化。这导致通信系统内的错误，并且必须被减轻以实现无错误的数据传输。在这个博士项目中，学生将开发新的实验系统，用于确定大气湍流对空间形状模式的影响。这些光束不以与高斯激光模式相同的方式传播，因此我们需要开发大气湍流对空间形状光的影响的详细模型。这些研究将导致新的自适应光学方案的开发，以充分减轻光在湍流环境中传播的影响。在结构光子学研究小组博士后研究人员的支持下，学生将完成这些方案的真实测试，并有可能被集成到BT的原型通信系统中。此外，与弗里堡大学合作，学生将探索创造新的空间模式集，增加了对湍流的弹性，并开发新的光学技术，用于对这些新型光学模式编码的信息进行解复用。这些技术将直接应用于光通信研究领域，但也将提供新的自适应光学方案，可用于远距离操作的遥感和成像系统。此外，使用空间形状光的环境传感已成为最近的热门话题，在这个博士项目中取得的进展将对这个新兴领域产生相当大的影响。该项目与130万英镑的EPSRC项目“用于接入部署的高维无线无源光网络（PON-HD）”相一致，该项目与阿斯顿大学、弗里堡大学和诺基亚贝尔实验室合作。

Cable-free optical communication systems are vital for building the communication networks of the future. Traditionally wireless connections have been based on radio or microwave systems. However, the capacity of these systems is substantially less than optical systems. Based on detailed analysis on the network requirements from British Telcom, free-space-optical links that incorporate advanced communication technologies such as space-division multiplexing will need to be deployed alongside more traditional fibre distributions meet the capacity requirements of their network in next 5-10 years. Space division multiplexing (SDM) is a communication scheme where laser beams are shaped in the spatial degree of freedom to offer additional communication channels. SDM is widely considered as the next frontier in high capacity communications, where researchers from around the world are highly active in this field. In this project, we will focus on the central issue of atmospheric turbulence. This turbulence arises from the temperature and pressure variations that occur in the air and result in changes to position, phase and shape of optical modes as they propagate through the atmosphere. This results in errors within communication systems and must be mitigated for error-free data transmission. In this PhD project, the student will develop new experimental systems for determining the effect of atmospheric turbulence on spatially shaped modes. These beams do not propagate in the same way as Gaussian laser modes, therefore we need to develop detailed models of the effects of atmospheric turbulence on spatially shaped light. These studies will then lead to the development of new adaptive optical schemes to fully mitigate the effects of light propagating in turbulent environments. Supported by post-doctoral researchers with the Structured Photonics Research Group, the student will complete real-world testing of these schemes and will potentially be integrated into prototype communication systems for BT. Further, working with the University of Frieberg, the student will explore the creation of new spatial mode sets that have increased resilience to turbulence and develop new optical techniques for the demultiplexing of information encoded with these new types of optical modes. These technologies will have direct application within the research field of optical communications, but will also provide new adaptive optics schemes that could be used within remote sensing and imaging systems that operate over long-distances. Further, environment sensing using spatially shaped light has become a recent hot topic, where the advances made within this PhD project will have a considerable impact on this emerging field. This project is aligned with the £1.3 m EPSRC project "High Dimensional Wireless Passive Optical Networking for Access Deployment (PON-HD)," that is in collaboration with Aston University, University of Frieberg, and Nokia Bell Labs.