Heterogeneously integrated Ⅲ-Ⅴ/Si single mode lasers based on a MMI-ring configuration and triplet-ring reflectors

摘要

In this paper we show that using a DVS-BCB adhesive bonding process compact heterogeneously integrated Ⅲ-Ⅴ/silicon single mode lasers can be realized. Two new designs were implemented: in a first design a multimode interferometer coupler (MMI) - ring resonator combination is used to provide a comb-like reflection spectrum, while in a second design a triplet-ring reflector design is used to obtain the same. A broadband silicon Bragg grating reflector is implemented on the other side of the cavity. The Ⅲ-Ⅴ optical amplifier is heterogeneously integrated on the 400nm thick silicon waveguide layer, which is compatible with high-performance modulator designs and allows for efficient coupling to a standard 220nm high index contrast silicon waveguide layer. In order to make the optical coupling efficient, both the Ⅲ-Ⅴ waveguide and the silicon waveguide are tapered, with a tip width of the Ⅲ-Ⅴ waveguide of around 500nm. The Ⅲ-Ⅴ thin film optical amplifier is implemented as a 3 μrn wide mesa etched through to the n-type InP contact layer. In this particular device implementation the amplifier section was 500μm long. mW-level waveguide coupled output power at 20°C and a side mode suppression ratio of more than 40dB is obtained.