Heterogeneously Integrated Evanescently Coupled Laser Systems on SiN Emitting in the Near-Infrared Band

Silicon nitride (SiN) with its ultra-low loss has emerged as a powerful passive platform for visible photonics [1], enabling a wide range of applications such as optical coherence tomography. Central to the development of such systems is the integration of laser sources operating in these shorter wavelength ranges. By using heterogeneous integration technologies such as micro-transfer printing, a variety of different devices can be integrated onto the Si and SiN wafers [2]. In order to create lasers however a challenge remains to be addressed: SiN has a much lower refractive index compared to the III/V semiconductor optical amplifier (SOA) which impedes the development of evanescently coupled lasers. By using CMOS-compatible hydrogenated amorphous silicon (a-Si:H) as an intermediate layer, the SiN-III/V transition can be achieved [3]. In this work, we present heterogeneously integrated evanescently coupled gallium arsenide (GaAs)-based lasers on SiN emitting below 1 μm by utilizing an a-Si:H intermediate layer.