Collaborative Research: Monolithic on-chip resonant cavity isolators for photonic integrated circuits

本研究的目的是展示半导体衬底上磁光隔离器的单片集成，并对其性能进行表征。这种方法是基于开发一种非互易谐振光学腔器件，该器件使用单片生长的多晶CeY铁石榴石作为磁光介质，以及用于坚固后加工微调的新型光敏硫系玻璃材料。这项研究将利用灰度处理技术和高阶Fano谐振腔结构来实现破纪录的器件性能。这项工作的智力优势是新材料和创新器件设计的结合。以前的片上隔离器在很大程度上依赖于磁光石榴石的晶片键合，传统上被认为与半导体上的单片集成不兼容。这项工作将把新的生长方法和材料与新的器件设计相结合，同时实现单片集成、无源器件操作、大隔离比、最小插入损耗、小占地面积以及优异的制造容差，从而解决高效片上光隔离的长期挑战。这项工作的更广泛影响包括它为光通信和光子信号处理领域提供了第一个实用的单片上隔离解决方案，从而潜在地改变了光通信和光子信号处理领域。当光子芯片中的组件数量增加时，组件之间的寄生反射可能会破坏激光器和电路运行的稳定性，从而严重危害电路功能。因此，随着光子集成水平的不断扩大，对片上隔离的需求变得势在必行。科学研究将与研究生课程开发、本科生培训以及为两所学院的K-12课堂开发实践模块紧密结合。

The objective of this research is to demonstrate monolithic integration of magneto-optical isolators on semiconductor substrates and to characterize their performance. The approach is based on developing a nonreciprocal resonant optical cavity device using monolithically grown polycrystalline cerium-yttrium-iron-garnet as the magneto-optical medium, and new photosensitive chalcogenide glass materials for robust post-fabrication trimming. The research will leverage gray-scale processing technologies and high-order Fano resonant cavity architectures to realize record-breaking device performance.The intellectual merit of this work is the combination of new materials and innovative device designs. Prior on-chip isolators have largely relied on wafer bonding of magneto-optical garnets, traditionally considered incompatible with monolithic integration on semiconductors. The proposed work will combine new growth methods and materials with new device designs to simultaneously achieve monolithic integration, passive device operation, large isolation ratio, minimal insertion loss, small footprint, as well as superior fabrication tolerance, thus resolving the standing challenge of efficient on-chip optical isolation.The broader impacts of this work include its potentially transformative impact on the field of optical communications and photonic signal processing by providing the first practical solution for monolithic on-chip isolation. When the number of components in a photonic chip increases, parasitic reflections between components can seriously jeopardize circuit functionalities by destabilizing laser and circuitry operation. The need for on-chip isolation therefore becomes imperative as the level of photonic integration continues to scale. The scientific research will be tightly integrated with graduate course development, undergraduate training, and development of hands-on modules for K-12 classrooms at both institutes.