A novel type of ultra-compact lateral-current-injection III/V photonic device integrated on SOI for electronic-photonic chip application

Abstract

An on-chip light source plays a determinant role in the realization of integrated photonic chips for optical interconnects technology. Several integration schemes of III/V laser on SOI platform for on-chip laser application have been proposed and demonstrated. However, most of those integration approaches do not provide effective solutions for the following two problems: effective light confinement/amplification in the III/V active region; and efficient light transfer/coupling between silicon and III/V waveguide. In this paper, a novel approach to integrate an ultra-compact Lateral-Current-Injection (LCI) laser on silicon-on-insulator (SOI) platform by direct wafer bonding technique is proposed and designed. The proposed LCI device has an ultra-thin thickness of 270 nm which is ~10 times thinner than the vertical current injection laser bonded on silicon. It has a confinement factor in the active region larger than 40% for 1 μm wide III/V active waveguide, which is the highest among all the other integration schemes proposed so far. An optical vertical interconnect access to transfer light efficiently between III/V and silicon layer is designed. The design of the shortest “Optical Via” of 4 μm which gives ~100% coupling efficiency is presented.