AI compute is ushering in the 3.2T optical era. We break down Mitsubishi Electric's latest paper: a 0.8 µm high-mesa EML, a Glass-AlN hybrid substrate, and wire-bond-free packaging that push modulation bandwidth past 100 GHz for next-gen CPO and GPU clusters.

Pluggable optics are hitting the front-panel limit, not a speed limit. Andy Bechtolsheim sandwiches a cold plate between two paddle cards to shrink 102.4T from 4U to 1U. His only doubt about CPO is attach yield, not the physics, and a Foxconn connector now sampling decides whether XPO works at 400G/lane.

How Broadcom's PHY lineup bridges switch silicon and optics: from 16:16 retimers and 400G 8:4 gearboxes in the 50G PAM-4 era to 800G 8:8 PHYs like the BCM8780x that pair Tomahawk 4-100G with proven 100G-per-lambda optics.

400G optical transceivers come in many variants. This guide walks through the common specs — SR8, DR4, FR8/LR8 and FR4/LR4 — covering reach, fiber type, wavelength, lasers, connectors and PAM4 lane rates.