Optical interconnect startup Quintessent Inc. today announced that it has raised $40 million in early-stage funding to gear up production of its hardware.
Cycle Capital led the Series A raise. It was joined by Goldman Sachs, Susquehanna International Group, Osage University Partners and several others. The investment follows a $11.4 million seed round in 2024.
Data center operators link together the artificial intelligence chips in their servers using fiber-optic cables. Data travels through fiber-optic cables in the form of light. Usually, that light is generated by a tiny laser-emitting chip embedded in network equipment. Quintessent offers a device dubbed a comb laser that it says is more durable and efficient than existing light sources.
Some network lasers generate light using microscopic structures called quantum wells. Those structures usually take the form of nanosheets made of two different materials with diverging optical properties. Quintessent’s device, in contrast, generates light using quantum dots. Those are nanostructures that usually have a spherical shape and are made of a single material rather than two.
Quantum dots are most commonly used to make high-end TVs. When an ultraviolet light beam is projected onto a quantum dot, the electrons that it hosts gain additional energy for a short amount of time. When the electrons return to their original energy level, they generate a beam of light that can be used to render frames on a TV or power optical networks.
Quintessent makes its quantum dots from a material called gallium arsenide. Electrons can move through gallium arsenide several times faster than through silicon, which means that quantum dots can more quickly switch between energy levels. That rapid switching makes it possible to generate laser pulses at higher speeds, which boosts network performance.
Network lasers usually rely on an array of complex supporting components to work. Those parts amplify light beams and mitigate voltage fluctuations that can reduce signal quality. Quintessent says its comb laser makes do with fewer supporting components than rival products, which translates into lower costs. Additionally, the company says, its technology uses 40% less power and can operate more reliably at high ambient temperatures.
The more data-containing light beams can travel through a fiber-optic link at once, the higher its throughput. Each beam has a different wavelength to avoid inference. Quintessent says that its comb laser can generate light beams with eight different wavelengths. Furthermore, the underlying technology can be extended to support higher wavelength counts and more parts of the spectrum.
“For the past several years, we have focused on building technologies designed to make optical connectivity fundamentally simpler to deploy and scale,” said co-founder and Chief Executive Officer Alan Liu. “With today’s news, Quintessent is starting its transition from tech development to a product-focused company.”
Quintessent will use its funding round to ramp up manufacturing of its comb laser and make reliability improvements. Down the road, the company plans to develop additional optical products including signal amplifiers that help improve connection reliability.