Imec and CST Global join forces on hybrid integrated InP light sources

Tech News

LEUVEN (Belgium), March 4, 2020 — Imec, a world-leading research and innovation hub in nanoelectronics and digital technologies, and CST Global, a UK-based designer and high-volume manufacturer of III-V compound semiconductors for photonics products, announce the successful integration of 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.

Silicon photonics (SiPho) technology has made great progress over the past decades and is used extensively in a variety of applications – from fiber-optic communications to sensing. Technology platforms have evolved into mature vehicles and are available to industry and academia for prototyping, low-volume and higher-volume manufacturing. But 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 has recently 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.

Joris Van Campenhout, Program Director Optical I/O at imec: “We are excited to work with CST Global to extend imec’s silicon photonics portfolio with hybrid integrated InP light sources. Our first passive laser assemblies have demonstrated excellent initial results. Throughout 2020, we will further optimize the precision and throughput of the laser assembly process; extend the functionality to include RSOA integration at 1310/1550nm wavelengths; and perform reliability qualification.

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. Early access through imec’s iSiPP200 prototyping services is anticipated by the first half of 2021.”

Antonio Samarelli, Integration Manager at CST Global: “We are extremely pleased to be working with imec on this project. The hybrid integration of InP light sources (DFBs and RSOAs), designed and fabricated on CST’s InP100 manufacturing platform, combined with the iSiPP platform allow the creation of powerful photonic integrated circuits (PICs) for advanced components with improved performance and lower cost in the future. We will continue to work closely with imec to extend the functionality and capabilities of the InP100 platform to meet the InP light source requirements of novel, advanced PICs for high volume commercial applications.

About imec

Imec is a world-leading research and innovation hub in nanoelectronics and digital technologies. The combination of our widely acclaimed leadership in microchip technology and profound software and ICT expertise is what makes us unique. By leveraging our world-class infrastructure and local and global ecosystem of partners across a multitude of industries, we create groundbreaking innovation in application domains such as healthcare, smart cities and mobility, logistics and manufacturing, energy and education.

As a trusted partner for companies, start-ups and universities we bring together more than 4,000 brilliant minds from over 97 nationalities. Imec is headquartered in Leuven, Belgium and has distributed R&D groups at a number of Flemish universities, in the Netherlands, Taiwan, USA, and offices in China, India and Japan. In 2018, imec’s revenue (P&L) totaled 583 million euro. Further information on imec can be found at

Imec is a registered trademark for the activities of IMEC International (a legal entity set up under Belgian law as a “stichting van openbaar nut”), imec Belgium (IMEC vzw supported by the Government of Flanders), imec the Netherlands (Stichting IMEC Nederland, part of Holst Centre which is supported by the Dutch Government), imec Taiwan (IMEC Taiwan Co.), imec China (IMEC Microelectronics (Shanghai) Co. Ltd.), imec India (Imec India Private Limited) and imec Florida (IMEC USA nanoelectronics design center).

About CST Global

CST Global is a UK producer of III-V compound semiconductors for photonics products. The company provides custom designed foundry services and standard, high-volume, lasers for high-growth, worldwide markets.

CST Global’s optical communications devices enable cloud computing, PON, 5G Fronthaul, artificial intelligence and quantum markets. Its optical sensing devices enable autonomous vehicle, consumer bio, hazard, security and augmented reality markets and its optical wireless devices are used in free-space communications such as LiFi.

CST Global is a partner in the UK and European Technology Consortium Programmes. The company employs 70 staff, of which 14 have PhDs, at its site in Glasgow, Scotland. The company exports over 90% of its production output to US, Chinese and European markets.

CST Global is a critical supply partner and approved vendor to some of the largest companies in the world, receiving new and repeat orders from Fortune 100 companies in every one of its vertical markets.

CST Global produces compound semiconductor devices in DFB, VCSEL, QCL and FP lasers formats using InP, GaAs, GaSb and GaN – based material formats.