title: Ultracompact tapered coupler for the Si/III-V heterogeneous integration.
abstract: An ultracompact tapered coupler, which is suitable for mode transformation between a 220 nm high silicon wire waveguide and a Si/III-V hybrid waveguide, is proposed for Si/III-V heterogeneous integration. The tapered coupler is composed of three sections. Since the tapered coupler avoids exciting the unwanted high-order modes in the III-V waveguide, the length of the tapered coupler can be dramatically shortened. In the proposed structure, the total length of the trisectional tapered coupler can be as short as 8 μm with a fundamental mode-coupling efficiency of over 95% in a bandwidth of over 100 nm. The alignment tolerance of the proposed structure is also analyzed.
authors.forename: Qiangsheng
authors.initials: Q
authors.lastname: Huang
authors.forename: Jianxin
authors.initials: J
authors.lastname: Cheng
authors.forename: Liu
authors.initials: L
authors.lastname: Liu
authors.forename: Yongbo
authors.initials: Y
authors.lastname: Tang
authors.forename: Sailing
authors.initials: S
authors.lastname: He