Insights

Our followers on LinkedIn recently voted photonic wirebonds as the most exciting advance in fibre-to-chip packaging today.

Photonic wirebonds are a way to physically and optically connect different photonic chips or optical components—similar in spirit to how metal wirebonds connect electronic chips, but using tiny 3D waveguides instead of metal wires.

The process typically uses two-photon polymerization (TPP), a high-resolution 3D laser lithography technique:

• Chips are placed near each other with relaxed alignment tolerances (a few micrometers)

• A focused femtosecond laser writes the desired waveguide shape directly into a photoresist

• The resist is developed, leaving behind a freeform optical waveguide that matches the on-chip waveguides

• This is like drawing a custom optical bridge in mid-air between the two photonic circuits

This is good for a few reasons:

💪 High coupling efficiency: Losses can be <2 dB per interface

💪 3D freedom: Can route light over various heights, angles, and lateral offsets

💪 Material independence: Can connect Si, InP, SiN, LiNbO₃, or others

💪 Relaxed positioning tolerances: No need for sub-micron chip placement

💪 Scalable packaging: Useful for multi-chip photonic modules

But this solution is not without its challenges. If you’re planning on using this, there are a few potential issues you need to be aware of:

🚨 For fibre-to-chip connections in mass production, you may need thousands of bonds per wafer/module, and TPP’s speed can be orders of magnitude too slow compared to lower spec. passive align-and-glue methods

🚨 Even with parallelised or faster writing systems, scaling to tens of millions of connections a year is a serious challenge

🚨 Every connection requires 3D position measurement and adaptive path generation, which increases process complexity

🚨 Photonic wirebonds are polymer-based waveguides. Polymers can suffer from ageing, UV exposure sensitivity, water uptake, and thermal expansion mismatch — especially under telecom-grade environmental tests.

🚨The absorption profile of the PWB material may limit the wavelengths you can use. 

Photonic wirebonds are most promising for chip-to-chip optical interconnects in heterogeneous photonic integration, where different material platforms—like InP lasers, silicon photonics modulators, and LiNbO₃ devices—need low-loss, flexible, and precisely aligned optical connections.

They enable custom 3D waveguide bridges that overcome strict alignment tolerances, making them ideal for multi-chip photonic modules, and specialised low-volume systems as in quantum photonics or aerospace applications. 

While slower than traditional methods, their ability to connect diverse chips with high optical performance and relaxed mechanical constraints makes them highly valuable in advanced photonic packaging scenarios where performance and flexibility outweigh throughput.

How do you see photonic wirebonds shaping the future of integrated photonics? Are they the game-changer for heterogeneous chip integration, or will other technologies take the lead?

September 2025, Bristol UK – We are thrilled to announce that Light Trace co-founder and CTO Dr Dominic Sulway has been recognised as one of the industry’s ‘most innovative minds’ in the Photonics100 2026 list. 

The list, assembled and published by Electro Optics, showcases the people whose work is shaping the future of photonics worldwide. It’s the first year that the UK leads the list, and Light Trace’s Dom is among 21 national honourees. 

“Every challenge photonics faces—whether technical, economic, or political—is matched by an opportunity to innovate,” said Warren Clark, Managing Director of Europa Science, publisher of Electro Optics. “The Photonics100 celebrates those leading the way.”

Dom said that the biggest challenge, and opportunity, for integrated photonics in the next year is moving from being a niche technology to a foundational enabler of next-generation data communications and quantum technologies. 

He said that Light Trace is “pushing the frontiers of what integrated photonics can achieve”, citing the LightPort - which is training up the next generation of photonics engineers, and LightBridge - a high-impact fibre-to-chip packaging solution due to be announced in the coming months.. 

While co-founding Light Trace has been the "defining adventure” of his career so far, he says that what he’s proudest of is the team’s daily accomplishments. 

“Seeing the ingenuity, dedication, and collaborative spirit they bring to complex challenges, and watching them consistently deliver groundbreaking work, is incredibly rewarding. This collective success, and the culture of innovation we have built, is my greatest source of pride because it is the engine that drives our company's mission to shape the future of integrated photonics.”

He points out that to do big things, you need to have a strong support network and “actively seek out discomfort”:

“Put yourself in rooms with people who know far more than you do, challenge them with questions, and learn from their expertise. Significant breakthroughs rarely happen in a vacuum; they often emerge from the conversations you least expect.”

Congratulations Dom for winning this prestigious award!

Light Trace Photonics is now hosted on MEETOPTICS, the world’s largest optics and photonics database. You’ll be able to find out all about our products and services on their site. 

MEETOPTICS is a specialised listings website to make photonics technologies more accessible. Their database helps photonics companies find the optical components they need without having to spend days searching.