Characterizations of InAs quantum dot lasers butt-joint coupled with silicon photonics waveguides

Abstract

InAs quantum dot (QD) laser heterostructures are grown by molecular beam epitaxy (MBE) system on GaAs substrates and fabricated. The InAs QD lasers exhibit comparable properties of the state-of-the-art QD lasers with the threshold current density J th and efficiency η i of 475A/cm 2 and 72.6%, respectively, at room temperature. The quantum dot laser emission is butt-joint coupled into silicon photonics waveguides by aligning the laser and silicon photonics chips with two translation stages. Due to the optical feedback to the laser cavity at the air/Si interface, the laser power self-pulsation and reduced threshold current density are observed. And the effective facet reflectivity, R eff , of 62.7% is obtained from the theoretically analysis of the laser characteristics. Furthermore, the silicon photonics waveguides interface is coated with the SiO 2 /TiO 2 antireflection (AR) coating layers, and no laser performance interference is observed owing the reduced optical feedback.