Silicon waveguide photonic functional devices based on direct bondingof heterogeneous crystals and their applications to photonic integrated circuits

作为实现基于硅波导的功能光子集成电路的基本技术，研究了一种表面激活的直接键合技术，分别用于集成III-V化合物半导体和用于光源和非互易器件的磁光晶体。基于该技术，制作了隔离度分别为30 dB和15 dB的硅波导光隔离器和环行器。此外，还实现了一个最大转换效率为97%的TE-TM模式转换器。apoapozed光栅耦合器在硅波导和表面光电二极管之间可以提供86%的随机偏振光耦合效率。研究了集成这些功能器件的光子电路的制作工艺。

As a fundamental technique for realizing functional photonic integrated circuits based on silicon waveguides, a surface-activated direct bonding technique has been investigated for integrating III-V compound semiconductors and magneto-optical crystals used for light sources and nonreciprocal devices, respectively. Based on this technique, silicon waveguide optical isolators and circulators are fabricated with an isolation of 30 dB and 15 dB, respectively. Also, a TE-TM mode converter is realized with a maximum conversion efficiency of 97 %. An apodized grating coupler can provides a coupling efficiency of 86 % for a randomly polarized light wave between a silicon waveguide and a surface mounted photo-diode. A fabrication process of photonic circuits integrating these functional devices is also investigated.