Integrated solutions for optical orbital angular momentum multiplexed transceiver

该项目涉及光学轨道角动量(OAM)多路复用收发信机的综合解决方案。这种传输技术是进一步提高光通信系统容量的一种有吸引力的方法。在过去的十年中，通过利用相干传输与先进的调制格式(DP-QPSK、QAM)相结合以及从标准的DWDM频率网格过渡到光超级信道来提高单光纤的容量。然而，标准光纤本身的传输能力往往受到非线性香农极限的限制。为了克服这一瓶颈，基于空分复用(SDM)的光通信引起了人们极大的研究兴趣。由于可以自由地选择用作MDM传输的正交信号载波的光纤模基，因此使用涡旋模基是明智的。与其他模型基相比，它们在(解)复用器中提供了较高的模式转换效率。目前，光学涡旋的产生、调制和检测都是由体光学器件提供的。将基于OAM的传输技术有效地应用于工业应用需要健壮性和重复性，而使用分立元件很难做到这一点。因此，能够在芯片上产生、传输和处理光学涡旋的紧凑型集成光学部件的开发是迈向基于OAM的可靠和具有能量和成本效益的信息系统的下一个关键步骤，并将这种数据多路复用技术应用于短距离场景。此外，这些组件的制造工艺应该与现有的光刻和微加工技术兼容。为了提供集成的发射器和接收器，关键组件，如空间多路复用器/多路分解器(SMUX)，应该在工业上可用的制造工艺中实现为光子集成电路。电子-光子集成电路(EPIC)允许这些(无源)光子电路与光电二极管等高速电子设备以及可能的基于SiGe技术的跨阻抗放大器共集成。因此，如何有效地实现基于光子集成电路的器件是本工作的主要挑战。我们提出了一种基于集成OAM发射器的发射机和一种全集成的片上接收器。将根据对现有制造平台的分析和对可能的集成微结构的详细模拟来确定适当的设计方法。将对生产的集成器件进行实验表征，以确认它们的功能，这些功能由分析和数值模型定义。此外，还将提供使用不同调制格式的连续波光信号和调制电信信号的系统级实验。

The proposed project deals with integrated solutions for optical orbital angular momentum (OAM) multiplexed transceivers. This kind of transmission technology is an attractive way to further enhance the capacity of optical communication systems.During the last decade, the capacity of single optical fiber was increased by exploiting coherent transmission combined with advanced modulation formats (DP-QPSK, QAM) and the transition from the standard DWDM frequency grid to optical superchannels. However, the transmission capacity of standard optical fiber itself tends to be restricted by the nonlinear Shannon limit. To overcome that bottleneck, optical communications based on the Spatial Division Multiplexing (SDM) has attracted significant research interest. Being free to choose the basis of fiber modes working as orthogonal signal carriers for MDM transmission, it is sensible to use the basis of vortex modes. They offer high mode conversion efficiency at the (de)multiplexer compared with the other modal bases.Currently, generation, modulation and detection of optical vortices are provided by bulk optical devices. The effective involvement of OAM-based transmission techniques into industrial applications requires robustness and repeatability, which is difficult to achieve with discrete components. Hence, the development of the compact integrated optical components, capable of on-chip generation, transmission and processing of optical vortices, is the next key step towards robust and energy- and cost-effective OAM-based information systems and to the involvement of this data multiplexing technique to the short-range scenarios. Moreover, the fabrication process of such components should be compatible with the existing lithography and micromachining techniques.In order to provide integrated transmitter and receivers, key components such as the spatial multiplexer / demultiplexer (SMUX) shall be realized as photonic integrated circuit in industrially available manufacturing processes. Electronic-photonic integrated circuits (EPIC) allow the co-integration of these (passive) photonic circuits and high-speed electronics like photodiodes and possibly trans-impedance amplifiers based on SiGe technology. Thus, the main challenge of the proposed work is the effective realization of the devices based on photonic integrated circuits.We propose to develop a transmitter based on integrated OAM emitter and a fully integrated on-chip receiver. The appropriate design approach will be determined in accordance with the analysis of available manufacturing platforms and detailed simulations of possible integrated microstructures. The produced integrated devices will be characterized experimentally to confirm their functionality, defined by the analytical and numerical models. Moreover, system-level experiments with the CW optical signal and the modulated telecommunication signals of different modulation formats will be provided.