Imec and CST Global of Glasgow, the designer and manufacturer of III-V compound semiconductors for photonics products, have integrated InP distributed feedback (DFB) lasers from CST Global’s InP100 platform into Imec’s integrated silicon photonics platform (iSiPP).

Interfaces for hybrid integration of InP DFB lasers and reflective semiconductor optical amplifiers (RSOA) will become available as part of Imec’s silicon photonics prototyping services in the first half of 2021, following further optimization and qualification work in 2020.

This joint imec-CST Global technology offering is expected to boost the adoption of silicon photonics in cost-sensitive applications, including optical interconnects, sensing, computing and beyond.

Until now, a widely available, cost-effective solution to integrate light sources in SiPho chips has been missing, hampering the adoption of SiPho in cost-sensitive markets.

Silicon itself does not emit light efficiently, so light sources made of III-V semiconductors, such as indium-phosphide (InP) or gallium-arsenide (GaAs), are typically implemented as separately packaged components.

Such external light sources typically suffer from higher coupling loss; a large physical form factor; and a substantial packaging cost.

Imec joined forces with CST Global to extend Imec’s SiPho technology portfolio with passively assembled, edge-emitting, InP DFB lasers and InP RSOAs.

This collaboration, which started in 2019, has now resulted in the first successful assemblies of C-band (1530-1565nm) InP DFB lasers onto imec’s iSiPP platform.

The InP lasers were ‘flip-chip’ integrated onto the SiPho circuits through a die-to-die bonding process, aligning efficiently and coupling >5mW into the SiN waveguides on the SiPho chip.

“We expect that the availability of these hybrid, integrated light sources will boost industrial uptake of SiPho devices in a variety of cost-sensitive markets,” says Imec’s Joris van Campenhout, “early access through Imec’s iSiPP200 prototyping services is anticipated by the first half of 2021.”