Photonics firm Quintessent raises $40m
Company begins sampling first product for AI optical interconnects
Santa Barbara-based optical interconnect company Quintessent has raised $40m in a Series A investment round. Quintessent also announced the start of customer sampling of its single-chip quantum dot-based DWDM comb laser – a new class of light source designed to simplify optical connectivity for rapidly scaling AI clusters.
The funding round was led by Cycle Capital, along with new investors Goldman Sachs XIG-Industry Ventures, Hina Liberty Capital, Susquehanna International Group, InterVest, Safar Partners, and Ciena. Existing investors including Foothill Ventures, M Ventures, Osage University Partners, and Sierra Ventures also participated in the round.
With the formation of the Open Compute Interconnect (OCI) MSA, the market has converged on wide-and-parallel dense wavelength division multiplexing (DWDM) architectures as a leading solution for optical scale-up networks, requiring many orders of magnitude more laser sources to interconnect future AI clusters. At the same time, the AI infrastructure buildout has met with a worldwide shortage of InP lasers.
Quintessent’s comb laser product generates eight precisely spaced wavelengths from a single laser with a single bias control. The architecture is built with GaAs O-band quantum dot gain material that is heterogeneously integrated on standard silicon photonics to enable high-volume, wafer-scale manufacturing.
By consolidating many lasers into one and eliminating supporting components, the architecture enables up to a 40 percent reduction in data movement power compared to “narrow-and-fast” architectures, according to the company. In addition, the design may be scaled to more (or fewer) wavelengths, and to additional CWDM wavelength bands, to enable simple bi-directional optical fiber communication with just one laser needed for each direction.
Quintessent first unveiled its comb laser technology earlier this year with live demonstrations to select customers and partners at OFC 2026. Today, the company is announcing the start of customer sampling; currently available as an evaluation kit, allowing customers to easily integrate the laser into system test beds.
The investment will be used for further maturation of Quintessent’s comb laser, including sampling, reliability / qualification, and ramping up manufacturing. This is the first product in Quintessent's broader roadmap of optical connectivity technologies spanning enabling components through integrated optical interconnect solutions for AI infrastructure.
Quintessent also plans to use part of the proceeds to develop other critically needed optical components - such as semiconductor optical amplifiers (SOAs) - and begin work on an optical engine for high reliability, availability, and serviceability (RAS) pluggable module interconnect applications within AI data centres.
“For the past several years, we have focused on building technologies designed to make optical connectivity fundamentally simpler to deploy and scale,” said Alan Liu, co-founder and CEO of Quintessent. “With today’s news, Quintessent is starting its transition from tech development to a product-focused company. We plan to use our investment to accelerate that transition and meet customer demand.”
