Semtech has begun sampling new physical medium dependent (PMD) chipsets designed for 1.6T multimode optical interconnects in AI data centers. Announced at ECOC 2025 in Copenhagen, the FiberEdge GN1878 VCSEL driver and GN1836 TIA deliver 200G per channel performance optimized for short-reach multimode links within AI training clusters.
The GN1878 and GN1836 are purpose-built to support the transition to 200G lanes, which the industry expects to ramp into high-volume manufacturing in 2026. By pairing with Broadcom’s 200G VCSEL and photodetector technology, the new components enable complete 1.6T SR8 optical solutions. Semtech positions multimode as a cost- and power-efficient alternative for sub-100m links in hyperscale environments where AI and ML workloads are scaling rapidly.
Semtech’s FiberEdge portfolio now spans multimode PMD solutions alongside its DirectEdge linear pluggable optics (LPO) platform. The company highlights its two decades of TIA design experience, extensive adoption by hyperscale operators, and manufacturing reliability as differentiators. The new 200G per channel devices are now sampling and will be demonstrated at ECOC 2025.
• GN1878: 200G VCSEL driver, optimized for multimode applications
• GN1836: 200G TIA, 250 μm pitch for high-density integration
• Complete 1.6T SR8 multimode chipset in collaboration with Broadcom
• Power-efficient and cost-optimized for short-reach AI cluster interconnects
• Available for sampling; ECOC 2025 booth #C3.129
“The 1.6T market inflection presents opportunities for diverse architectural approaches and multimode technology will play an increasingly important role alongside single-mode solutions,” said Amit Thakar, vice president of signal integrity product marketing at Semtech.
🌐 Analysis: The move to 200G lanes is a cornerstone of the industry’s 1.6T transition, with multimode optics carving out a role in cost- and energy-sensitive short-reach AI data center links. Semtech’s alignment with Broadcom reflects a broader ecosystem push to ensure interoperable multimode solutions as hyperscalers weigh power efficiency against the reach advantages of single-mode optics. With companies such as AOI also emphasizing VCSEL-based approaches, competition is intensifying between multimode and emerging LPO single-mode architectures for intra-data center AI interconnects.
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