STMicroelectronics has recently launched the next generation of optical interconnect technologies to support better connectivity for data centers and AI clusters, making it a truly innovative solution that allows customers to integrate many complex components on the same chip.
During an interaction with Electronics media, Vincent Fraisse, General Manager of the RF & Communication Division at STMicroelectronics, focused on the need for power-efficient, high-performance connectivity between servers and GPUs and how STMicroelectronics’ proprietary silicon photonics technology is the fastest growing technology for pluggable & co-packaged optics..
Electronics Media: Kindly provide an overview of STMicroelectronics’ vision in the domain of Cloud Optical Interconnects?
Vincent Fraisse: At STMicroelectronics, we envision a world where devices can sense, autonomously infer, and intelligently actuate. This vision is built on three key pillars: Edge AI, Security, and Cloud AI. These pillars are crucial for enabling an accelerated AI infrastructure where all server elements are optically interconnected.
Our focus is on tackling the increasing demand for high performance and greater energy efficiency in data centers. With the surge in AI-driven workloads, it is imperative to optimize energy consumption both per unit of compute and per bit transferred.
Electronics Media: Could you elaborate on the role of optical interconnects in AI and cloud computing?
Vincent Fraisse: Certainly. AI’s rapid growth is driving the need for better performance and higher bandwidth while ensuring energy efficiency in data centers. The backbone of this connectivity is the optical interconnects, which facilitate data transfer through electro-optical transceivers.
Each optical fiber in a data center is equipped with an electro-optical transceiver that converts electrical signals into optical signals and vice versa. These transceivers comprise three major semiconductor components:
- A microcontroller (MCU) that controls transceiver operations.
- An electronic IC (EIC) that drives the optical source (laser) and amplifies signals.
- A photonic IC (PIC) that performs the conversion between optical and electrical signals.
STMicroelectronics offers the best BiCMOS technology for EIC devices and has pioneered Silicon Photonics (SiPho) solutions, which are increasingly becoming the industry standard for pluggable and co-packaged optical (CPO) modules.
Electronics Media: When we talk about Silicon Photonics. What advantages does SiPho bring to optical transceivers?
Vincent Fraisse: SiPho technology is poised to dominate the transceiver market because of its numerous advantages over traditional technologies like EML and VCSEL. It offers higher performance, longer transmission range, and better power efficiency.
Moreover, SiPho enables the development of Linear Pluggable Optics (LPO) and Linear Receiver Optics (LRO), which reduce system power consumption by eliminating the need for DSPs. This directly contributes to energy efficiency, which is a critical requirement for AI and cloud applications.
Electronics Media: ST has recently announced the PIC100 platform. Can you tell us more about it?
Vincent Fraisse: Absolutely. The PIC100 is STMicroelectronics’ brand-new Silicon Photonics technology platform. It is the only pure silicon-based 300mm technology capable of supporting up to 200 Gigabits per connection lane.
PIC100 benefits from ST’s advanced 300mm fabrication facility in Crolles, France, ensuring high yield and manufacturability. This technology is a game-changer in terms of compactness, efficiency, and scalability. It enables direct fiber attachment at the edge of the photonic IC, reducing system losses—a persistent challenge in optical interconnects. We expect volume production to commence in the second half of 2025.
Electronics Media: ST has also announced advancements in BiCMOS technology. What are the key differentiators of the B55X platform?
Vincent Fraisse: The B55X is the most advanced BiCMOS technology in our portfolio. It builds upon our expertise in BiCMOS manufacturing by offering improved linearity and noise performance, making it ideal for high-speed applications like 200G per lane transceivers.
The key differentiators of B55X include:
- High FT and FMax, delivering better performance.
- Lower noise levels, essential for high-speed optical data transmission.
- Excellent linearity, which enhances power efficiency and enables DSP-less transceiver solutions.
Our BiCMOS technology is already being widely used in RF front-end modules and is now gaining traction in the optical interconnect market.
Electronics Media: With growing competition in the optical interconnect space, how does ST position itself against other players?
Vincent Fraisse: ST differentiates itself through our integrated manufacturing approach and technological leadership. We are a fully independent IDM (Integrated Device Manufacturer), and our 300mm silicon photonics and BiCMOS manufacturing capabilities provide significant advantages in scalability and yield.
Additionally, we have entered strategic collaborations with hyperscalers like AWS and leading optical transceiver manufacturers. These partnerships validate the industry’s confidence in our technology and allow us to bring best-in-class solutions to the market.
Electronics Media: Apart from hyperscalers, what other market segments do you see as potential adopters of your optical interconnect technologies?
Vincent Fraisse: While hyperscalers are our primary customers, other key market segments include:
- Data Center Interconnect (DCI) providers
- AI cluster developers
- High-performance computing (HPC) manufacturers
- Enterprise networking solutions
Silicon photonics is also becoming the de facto standard for Chip-to-Chip GPU interconnects. As AI workloads become denser, there is an industry-wide shift from copper to optical solutions for GPU connectivity. ST’s SiPho and BiCMOS technologies are well-positioned to support this transition.
Electronics Media: Looking ahead, what advancements is ST exploring in Silicon Photonics for AI and cloud computing?
Vincent Fraisse: The next frontier for silicon photonics is Optical I/O, where optical fibers will be directly connected to GPUs and CPUs. This will enable ultra-compact, high-speed, and low-power data transfer, significantly enhancing AI infrastructure efficiency.
To achieve this, we are working on:
- Compact modulators like ring modulators and electro-absorption modulators.
- Through-Silicon Vias (TSVs) to improve signal integrity and reduce power consumption.
- Higher integration of BiCMOS and SiPho components for better performance.
Electronics Media: Finally, do you see Co-Packaged Optics (CPO) becoming the dominant interconnect solution?
Vincent Fraisse: CPO is undoubtedly an important trend, especially for the back-end of racks in AI data centers. However, it will coexist with pluggable transceivers, which will continue to evolve with higher throughput and improved efficiency.
CPO faces challenges like serviceability, thermal management, and reliability. ST is addressing these challenges by developing advanced BiCMOS and SiPho solutions that optimize signal quality, power consumption, and scalability.
Electronics Media: What does the roadmap for ST’s optical interconnect technologies look like?
Vincent Fraisse: We are actively working with major transceiver manufacturers and hyperscalers to bring our SiPho and BiCMOS technologies to mass production. We expect a significant ramp-up in the second half of 2025, with multiple design wins at Silicon Photonics design houses.
Furthermore, as an Integrated Device Manufacturer (IDM), ST has full control over the entire value chain—from chip design to fabrication, assembly, and testing. This approach ensures supply chain resilience and provides a competitive advantage for our customers.
Electronics Media: Looking ahead, what impact do you see ST’s innovations having on the industry?
Vincent Fraisse: The future of AI and cloud computing hinges on high-speed, low-power optical interconnects. Our SiPho PIC100 and BiCMOS B55X are setting new benchmarks in optical transceiver technology, paving the way for more efficient and scalable data center architectures.
As AI workloads continue to expand, the shift from copper-based solutions to optical interconnects will be essential in meeting both performance and sustainability goals. ST’s innovations represent a significant leap forward, reinforcing our position as a key enabler in the digital era.
Electronics Media: Thank you, Vincent, for sharing these insights. It’s clear that STMicroelectronics is at the forefront of next-generation optical interconnect technologies.
Vincent Fraisse: Thank you. It was a pleasure discussing our latest advancements, and I look forward to seeing how our innovations shape the future of AI and cloud computing.
For more information visit STMicroelectronics.
