Lightspring raises €3.5M to tackle photonic chip manufacturing bottleneck

French startup Lightspring has raised €3.5 million in seed funding from venture capital firms Atlantic and OVNI Capital, as well as Concept Ventures, Ixcore, Plug and Play Ventures, and industry business angels. The investment will help Lightspring commercialize its 3D optical coupling technology for photonic integrated circuits (PICs).

Lightspring designs and manufactures the optical interfaces of PICs, turning photonic packaging into a programmable manufacturing step. By applying 3D lithography directly onto the chip, the company eliminates the most expensive and least reproducible step in the photonic chip manufacturing process. This move, known as co-packaged optics, moves the optical interface closer to compute and reduces the overall cost of a PIC by around 50 percent.

The company's core technology uses a single process step to fabricate optical coupling structures such as microlenses, 3D waveguides, and beam-shaping elements. This eliminates the need for precision pre-alignment, resulting in lower optical loss, higher throughput, and improved yield. The technology originates from research at the FEMTO-ST Institute in Besançon, a leading center for optics and micro-nanotechnology in Europe.

Lightspring's co-founder and CEO, Grégoire Bonnat, stated that the funding will turn lab results into industrial building blocks, enabling the technology to scale and become a key component in AI infrastructure. The investment will also support the development of Lightspring's Process Design Kit (PDK) and design tools, expand the team, and qualify its fabrication process for industrial use.