Optics have been critical for network switches especially at 800 Gbps and evolving to 1.6T from cost, density, power efficiency and performance perspective. Arista has been driving major innovations in optics to power networking for AI applications. In this section, we will cover the optics landscape and highlight the evolution to high-density 1.6T optics for AI networking.

Arista identifies power, cost, and reliability as the three pillars of optical innovation. While the OSFP form factor has been incredibly successful, projected to reach 100 million modules in 2026, it is reaching its thermal and density limits at approximately 35 watts. To meet the demands of next-generation AI networks, Arista introduced XPO, or extra dense pluggable optics. This new form factor is designed for 1.6T and beyond, offering a 4x improvement in system-level density compared to OSFP. By utilizing a two-tier card design and liquid cooling, XPO can handle thermal loads of up to 400 watts. This shift to liquid cooling not only manages heat but also significantly improves reliability by keeping optical components at lower, more stable temperatures, effectively reducing failure rates by five to eight times.

Beyond density and cooling, the evolution of optics includes a push for power-efficient architectures like Linear Pluggable Optics (LPO), which can reduce power consumption by 60% by eliminating internal retiming. Arista is also exploring Co-Packaged Optics (CPO) as a complementary solution, though XPO currently offers broader versatility across the various reaches required for scale-up, scale-out, and scale-across fabrics. While CPO is compelling for high-density, short-reach DR optics, it faces challenges regarding universal reach and a maturing supply chain. XPO, conversely, supports the full spectrum of connectivity from short-reach copper and fiber to long-distance coherent optics like ZR and ZR+, which are essential for the IP-over-DWDM architectures used in scale-across regional networks.

Arista remains committed to an open ecosystem, having established XPO as an open multi-source agreement (MSA) with over 100 partners, including major module vendors and system competitors like Cisco and Nokia. This open approach ensures a robust supply chain and allows customers to avoid proprietary lock-in while transitioning to liquid-cooled, high-density environments. The transition to XPO also enables data center operators to shrink the footprint of their networking racks, freeing up more physical space and power for revenue-generating GPU compute. As speeds advance toward 1.6T and 3.2T, the combination of denser form factors, advanced liquid cooling, and open standards will be the foundation for sustaining the growth of generative AI infrastructure.

Presented by Vijay Vusirikala, Distinguished Lead. Recorded live at Networking Field Day 40 in San Jose on April 9, 2026. Watch the entire presentation at https://techfieldday.com/appearance/arista-presents-at-networking-field-day-40/ or visit https://TechFieldDay.com/event/nfd40 or https://Arista.com/ for more information.