Lightspring

Lightspring uses two-photon polymerisation—3D lithography—to fabricate optical coupling structures like microlenses, 3D waveguides and beam-shaping elements directly onto photonic chips. It's turning fibre-, laser- and chiplet-to-chip packaging into a programmable manufacturing step, targeting coupling losses below 0.5 dB per interface.

Packaging can account for roughly half the cost of a photonic integrated circuit, versus about 20% for the foundry step—so the bottleneck has moved from making the chip to connecting it. Lightspring is attacking exactly that neglected margin.

The company is a spinout from the FEMTO-ST / CNRS ecosystem in Besançon, co-founded by CEO Grégoire Bonnat with CNRS Research Director Daniel Brunner. Its core IP is what the company says is the first Process Design Kit dedicated to 3D optical coupling.

Pairing a CEO with a CNRS Research Director gives the founding team both a commercial lead and deep-tech research depth rooted in a recognised photonics ecosystem. The PDK approach—with design cycles under two weeks—suggests a team building for repeatable manufacturing, not one-off lab demos.