How Hybrid Integration Builds on Silicon Photonics Foundation
It’s no secret that optical transceivers built on silicon photonics technology is in need of delivering more speed and lower energy output to the global datacenter market. While devices have met demand for better performance and increased data throughput, they have also increased the bill of materials, resulting in products heavy in components and complexity. Engineers have also run into obstacles as they tried to integrate more functionality into their silicon-photonics designs. The ability to multiplex and demultiplex signals, for example, in order to use less optical fiber is a remaining challenge in silicon photonics. Available transceivers built on silicon photonics continue to use external demultiplexers to help meet their performance targets.
Still, silicon photonics retains many advocates who believe it can address problems the industry faces because it relies on high-performance light solutions and not traditional commodity-based materials. As Technologist Magazine pointed out in 2017, when silicon photonics was emerging in the marketplace, the semiconductor’s long-standing reliance on copper connections was creating obstacles to innovation.
“Limited bandwidth, current leakage and crosstalk between adjacent wires produce bottlenecks for computing innovators. There are also practical concerns like the space copper wires take up, the power they consume and the heat they emit,” author Ben Skuse wrote in the publication.
The Optical Interposer: A Bold New Solution
The dream solution would be a hybrid model that involves the development of low-cost, small-footprint products with higher performance than conventional options. And pushing those solutions out through FR (far reach) devices that can go as long as 10 kilometers (6.5 miles). Such innovation would drive the next generation of products that would create faster, more reliable data communications. Increased data throughput and a reduction in the bill of materials and footprint can bring possibilities for engineers who aim to deploy innovations in cutting-edge industries such as datacenters, health tech, 5G, artificial intelligence, and electric vehicles.
As Nature Magazine notes, “Hybrid platforms combining different photonic technologies in a single functional unit have great potential to overcome the limitations of monolithic photonic circuits.”
At POET Technologies, CEO Dr. Suresh Venkatesan was a pioneer in developing a hybrid-integration solution for photonics, i.e., the ability to use “best-of-breed” components regardless of the material set that they are made from. His understanding of the industry’s needs grew out of his decades as a technologist and also his dialogue with corporate leaders.
“For a lot of applications it has become fairly clear that standard silicon scaling is just not going to get there and that silicon needs to be augmented with other capabilities, and that’s where the hybrid-integration concept comes about,” Venkatesan says in a recent video interview.
Indications of the eagerness for a next-generation solution could be seen at the Optical Fiber Conference (OFC) 2022 in March. Following live demonstrations of the company’s 200G FR4 Transmit and 400G FR4 Receive Optical Engines — innovations based on the patented POET Optical Interposer — conversations have deepened with numerous established enterprises. In March, POET also announced it will create an 800G Receive (RX) Optical Engine. The company’s research shows that an FR4 device that achieves 800G performance with two 400G fiber attachments working in concert would be a dominant product for the industry. For one thing, there would be only four fibers instead of 16. It would also reach between 2–10 kilometers, an improvement from DR8 solutions that are limited to 500 meters or less. Those features are attractive to potential clients who want a smaller form factor and more simplicity in design architecture.
The Optical Interposer represents the first-ever chip-scale integration of electronics and photonics into a single platform. As of April, the company has six committed customers and are in active discussions with more than 30 others, evidence that hybrid integration is indeed catching on.
“With the Optical Interposer we have a way to integrate different material systems onto a common base and there are many ways to do that,” Venkatesan points out.
POET solutions are produced entirely at wafer level, reducing the assembly cost by as much as 50% over standard solutions. At 3.5mm x 9mm, the POET Optical Engine is four times smaller than conventional chip-on-board solutions and has only six components (vs. the 30 typically used by other vendors). It reduces heat and energy usage by 30% over competing designs and meets or exceeds all industry standards.
“What we’re doing is revolutionary, not just evolutionary,” says James Lee, POET’s Vice-President and General Manager of its Singapore operations. “It’s an opportunity for us to truly transform the industry.”
MORE CONTENT:
How POET’s Solutions Can Grow A.I. Technology
