Monolithic magneto-optical isolators for on-chip photonic integration

非技术：光隔离器是光电二极管的光学类似物：它们允许光在一个方向上传输，但阻止光在相反方向上传播。隔离器是光子集成电路中防止电路各部分间有害串扰、稳定电路运行的重要器件。然而，目前的光学隔离器体积庞大，不兼容集成在光子芯片上。本项目旨在开发基于新型磁光氧化物材料的器件技术，以创建适合与硅光子电路直接集成的光隔离器。通过该计划开发的隔离装置将在光通信和光子信号处理领域产生直接影响。除了数据通信，它还将在自旋电子学、磁光传感和磁等离子体等新兴应用中发挥关键作用。科学研究将与大规模开放在线课程开发、高中、本科和研究生培训以及K-12课堂教育模块设计紧密结合。技术：光隔离器，一种只允许光在一个方向上传输的器件，是光子集成电路的关键部件，也是非互易光学器件的一个更大类别的例子。尽管它们至关重要，但由于磁光氧化物与普通半导体衬底之间的晶格常数和热膨胀系数不匹配较大，因此在片上集成光隔离器一直是一项具有挑战性的任务。该计划旨在通过假设涉及材料工程和设备创新的双管齐下的方法来填补空白。该项目将采用单片生长的多晶掺铈钇铁石榴石作为磁光介质，开发一种非互易隔离器/环行器装置，并采用新颖的器件设计来提高器件性能。该研究将使隔离器器件同时实现单片集成、无源器件工作、大隔离比、最小插入损耗、小占地以及优越的操作带宽，从而解决片上光隔离的长期挑战。

Non-technical: Optical isolators are optical analogs of electrical diodes: they allow light to be transmitted in one direction but block light propagation in the opposite direction. Isolators are essential components for photonic integrated circuits to prevent harmful cross-talk between different parts of circuits and stabilize circuit operation. However, current optical isolators are bulky devices not compatible with integration on photonic chips. This program aims to develop the device technologies based on novel magneto-optical oxide materials to create optical isolators amenable to direct integration with silicon photonic circuits. The isolator device developed through this program will have an immediate impact in the fields of optical communications and photonic signal processing. Besides data communication, it will also play a pivotal role in emerging applications such as spintronics, magneto-optical sensing, and magnetoplasmonics. The scientific research will be tightly integrated with Massive Open Online Course development, high school, undergraduate and graduate student training, as well as educational module design for K-12 classrooms.Technical: Optical isolators, devices that allow light transmission in only one direction, are critical components of photonic integrated circuits, and exemplify a larger class of nonreciprocal optical devices. Despite their critical importance, integration of optical isolators on-chip has been a challenging task due to the large lattice constant and coefficient of thermal expansion mismatch between magneto-optical oxides and common semiconductor substrates. This program aims at filling the gap by assuming a two-pronged approach involving both material engineering and device innovation. The program will develop a nonreciprocal isolator/circulator device using monolithically grown polycrystalline Cerium-doped Yttrium Iron Garnet as the magneto-optical medium, and incorporate novel device designs to enhance device performance. The research will lead to an isolator device simultaneously achieving monolithic integration, passive device operation, large isolation ratio, minimal insertion loss, and small footprint, as well as superior operation bandwidth, thus resolving the standing challenge of on-chip optical isolation.