The optical interconnect supply chain is entering a simultaneous step-function across 8+ companies -- gain-chip supply at 3x demand, SiGe fabs oversubscribed through 2027, and silicon photonics entering volume production create a $15B+ addressable market by 2029

The 1.6T transceiver cycle is real and accelerating far faster than prior generational transitions. The 800G-to-1.6T transition is compressing from an 18-month cycle to 6-9 months, with volume 1.6T orders already secured while 800G ramps have barely begun. NVIDIA's $2B+ equity investments in Coherent and Lumentum have declared co-packaged optics the winner for scale-up networking, while pluggables still dominate scale-out. AMD's Helios collaboration with Celestica confirms multi-vendor CPO demand. The supply chain constraints are severe and multi-layered. Semtech's gain chip demand exceeds supply by 3x. GlobalFoundries' SiGe capacity is oversubscribed through 2027. Tower Semiconductor has $1.3B in contracted 2027 silicon photonics revenue backed by $290M in prepayments. AXT's indium phosphide backlog has doubled to over $100M. Veeco received $250M+ in InP laser tool orders. Coherent is doubling InP capacity by end-2026 and more than doubling again by end-2027. AAOI is expanding laser fab capacity 350% by 2027. Fabrinet's total capacity is growing from $4.8B to $8.5B. The TAM expansion is staggering: Ciena now expects its addressable market to double to $50B by 2029, and Nokia raised its AI/cloud addressable market CAGR from 16% to 27%. Credo targets $600M+ in optical revenue in FY27. Marvell sees its DCI line of sight to $1B annualized. The optics buildout simultaneously drives demand in semis (SiGe, InP substrates, photonic ICs), equipment (III-V fab tools, test), and the optical module/networking stack.