PicoJool raises $27.5M Series A to scale optical interconnects for AI data centers

PicoJool, a Palo Alto startup developing optical interconnects for AI infrastructure, announced on September 24 that it has raised $27.5 million in Series A funding. The round was led by Socratic Partners, with participation from Hudson River Trading (HRT). Together with an earlier $12 million seed round led by Playground Global, the financing brings the company's total raised to $39.5 million.

Lasers instead of copper

PicoJool builds optical links based on vertical cavity surface emitting lasers (VCSELs), a type of semiconductor laser diode that carries data as light signals through optical cables instead of copper wire. The company says its chips and modules improve both the performance and the energy efficiency of large AI accelerator clusters, in which hundreds or thousands of processors constantly exchange data packets. Its product line is designed to scale from 800G to 1.6T, 3.2T and beyond, and includes high-speed 100G and 200G VCSEL products alongside lower-power microVCSEL configurations: 50G NRZ for optical compute interconnects and 64G NRZ/PAM4 for PCIe 6.0-based near-package optics (NPO).

200G per lane and early sampling

The Series A follows the June unveiling of PicoJool's 200G VCSEL and microVCSEL family for scale-up AI data centers. The 200G products exceed 37GHz of bandwidth, and the portfolio includes quad 100G, quad 200G and 32x50G NRZ microVCSEL configurations that give customers several routes to 1.6T connectivity, depending on bandwidth, power and system requirements. PicoJool has begun early sampling of its chip-level VCSEL products ahead of broader availability.

"Reaching 200G per lane proved that the performance is there. Our focus now is execution," said founder and CEO Al Yuen. According to the company, the funding will expand its teams and facilities in the United States and Taiwan, help qualify products with customers and move the portfolio from chip-level VCSELs and microVCSELs into active optical cable (AOC) and NPO modules. PicoJool is working with WIN Semiconductor and other gallium arsenide (GaAs) foundries to ready its 200G VCSELs for production.

Why it matters

AI clusters keep growing in processor count, and the volume of data moving between accelerators now strains the copper interconnects traditionally used to link them. "The network is the AI, and connectivity is becoming one of the defining constraints on performance," said Pat Gelsinger, general partner at Playground Global and former CEO of Intel. "The industry needs a solution that can increase bandwidth while sharply improving power and cost." Socratic Partners general partner Greg Waters said PicoJool combines a proven team with an approach that brings VCSEL technology's cost and manufacturing advantages to AI-scale bandwidth and power needs.