AUO, Largan Micro LED debate highlights optical communications uncertainty

The AUO-Largan dispute is not about whether Micro LED can work in optical communications—it is about whether LED's nanosecond-scale electroluminescent modulation can keep pace with 1.6T CPO architectures. Largan's skepticism is technically grounded: LED response times lag VCSEL/EML by orders of magnitude, and multimode fiber intermodal dispersion further caps achievable bandwidth. AUO's insistence betrays a panel maker's strategic anxiety—Micro LED is its few remaining high-value differentiators; abandoning it means retreating to a commodity red ocean. The real risk is temporal, not technical. NVIDIA's silicon-photonics CPO is already validated in the Rubin roadmap; Broadcom's Bailly series is shipping. Customer qualification windows are 12 to 18 months. If Micro LED cannot cross from lab to volume production before 2026, it will be permanently marginalized in datacenter interconnect. For the Taiwan, China optoelectronics supply chain, a deeper vulnerability persists: driver ICs and epi-wafers remain dependent on Japanese and Korean upstream suppliers. Any expansion of U.S. export controls would directly fracture this chain's supply security. My call: within 18 months, CPO will consolidate around silicon photonics plus VCSEL as the dominant path. Micro LED's optical role shrinks to chip-to-chip short-reach interconnect—a niche. AUO must lock in a hyperscale customer for joint validation before Q2 2026, or the market will stop funding the narrative.