News: Optoelectronics
24 January 2025
Quintessent and IQE establish quantum dot laser & SOA epiwafer supply chain for AI optical interconnects
Quintessent Inc of Santa Barbara, CA, USA — which specializes in heterogeneous integration of quantum dot lasers and silicon photonic integrated circuits (PICs) — and epiwafer and substrate maker IQE plc of Cardiff, Wales, UK have partnered to establish what is said to be the world’s first large-scale quantum dot laser and semiconductor optical amplifier (SOA) epitaxial wafer supply chain. Supported by purchase order commitments from Quintessent, the collaboration will see IQE deliver production quantities of epitaxial wafers to Quintessent throughout 2025.
The ever-growing demand for larger parameter models for AI training and inferencing necessitates the interconnectedness of disaggregated compute and memory resources with high bandwidth, low latency, low energy consumption and high reliability, which can only be met with advanced optical interconnects, say the firms. The laser source within the optical interconnect is a major driver of all these performance metrics, but conventional laser technology and the associated III-V supply chain falls short of AI’s future demands. Reliability of the laser is especially crucial and is perceived to be a limiting factor in scaling optical interconnects for future AI ‘factories’. The use of quantum dot material provides a foundational breakthrough for laser and SOA technology, resulting in longer lifetimes for enhanced reliability, wider operating temperatures, higher wall-plug efficiency, lower noise, and higher immunity to back reflections, the firms add.
The supply of high-quality and high-volume quantum dot epitaxial wafers for laser sources and SOAs have been limited until recent breakthroughs were achieved by Quintessent and IQE, which have been in the making for the past decade, including research that was spun out of John Bower’s laboratory at the University of California, Santa Barbara. Transitioning the gallium arsenide (GaAs)-based quantum dot research to high-volume production has resulted in highly optimized and high-performing gain material on 6-inch diameter epitaxial wafers that can produce several hundreds of millions of edge-emitting lasers and SOAs per year.
“The performance, cost and reliability advantages that quantum dot-based lasers and amplifiers enable over their quantum well counterparts are exactly what our customers are demanding to address the soaring need for optical connectivity in AI-driven compute,” says Quintessent’s CEO & co-founder Alan Liu. “Through our partnership with IQE, we have brought this transformative technology to scale, positioning us to be the leader in delivering solutions leveraging quantum dot laser and SOA technology,” he adds.
“Our long-term partnership on commercial products and DoD [Department of Defense] programs has yielded QDL [quantum dot laser] wafers with excellent reproducibility and lasing performance,” says IQE’s chief revenue officer Mark Furlong. “In addition to expertise in volume manufacturing of epitaxial wafers, our partnership with Quintessent demonstrates IQE's strong track record in scaling the manufacturing readiness of new product into volume production.”
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