The heterogeneous integration of silicon with III-V materials provides a way to overcome silicon's limited optical properties toward a broad range of photonic applications. Hybrid modes are a promising way to make heterogeneous Si/III-V devices, but it is still unclear how to engineer these modes to make photonic crystal cavities. Herein, using 3D finite-difference time-domain simulation, a hybrid Si-GaAs photonic crystal cavity design enables cavity mode confinement in GaAs without directly patterning that operates at telecom wavelengths. The hybrid cavity consists of a patterned silicon waveguide nanobeam that is evanescently coupled to a GaAs slab with quantum dots. We show that by engineering the hybrid modes, we can control the degree of coupling to the active material, which leads to a tradeoff between cavity quality factor and optical gain and nonlinearity. With this design, we demonstrate a cavity mode in the Si-GaAs heterogeneous region, which enables strong interaction with the quantum dots in the GaAs slab for applications such as low-power-threshold lasing and optical bistability (156 nW and 18.1 $μ$W, respectively). This heterogeneous integration of an active III-V material with silicon via a hybrid cavity design suggests a promising approach for achieving on-chip light generation and low-power nonlinear platforms.
Lasing from SOI-integrated GaAsSb nanowires via resonator-driven optical feedback
Walter Schottky Institute, TUM School of Natural Sciences, Technical University of Munich（慕尼黑工业大学）；Institute of Physics and Astronomy, Technical University Berlin（柏林工业大学）
Universidad Autónoma de Madrid（马德里自治大学）；Università di Padova（帕多瓦大学）；Wrocław University of Science and Technology（弗罗茨瓦夫科技大学）；EPFL（洛桑联邦理工学院）；Univ Rennes, INSA Rennes, CNRS, Institut FOTON – UMR 6082（雷恩大学、雷恩国立应用科学学院、法国国家科学研究中心、FOTON研究所）；Instituto Nicolás Cabrera, Universidad Autónoma de Madrid（尼古拉斯·卡布里拉研究所，马德里自治大学）；Instituto de Física de la Materia Condensada (IFIMAC), Universidad Autónoma de Madrid（凝聚态物理研究所（IFIMAC），马德里自治大学）
