ELSFP

Overview

ELSFP (External Laser Small Form-factor Pluggable) is a form-factor specification for pluggable laser modules used in co-packaged optics (CPO) systems. The design intent is to keep the laser source field-replaceable — as a standard FRU — rather than integrating it permanently into the compute tray, which would make laser failure a compute-outage event.

Even with ELSFP-style laser modules, faceplate real estate consumption remains a constraint: the form factor occupies significant space on the tray faceplate, limiting the path from 100T to 200T and higher system densities. The OCP community has had ongoing discussions about ELSFP-style laser tray solutions. Marvell's position is that laser external placement is ultimately an industry-wide problem requiring collective resolution, and the optimal long-term approach is to move laser sources completely out of the compute tray into separate infrastructure — enabling higher density while maintaining serviceability.