Researchers demonstrate cost-effective, scalable, thin-film lithium PICs

A joint effort from HyperLight and Harvard University has achieved a technical milestone for lithium niobate photonic integrated circuits (PICs). The work demonstrates lithium niobate PICs’ compatibility with mass production technologies. The technology aims to alleviate bottlenecks in data center and telecommunications networks while minimizing energy consumption.

The team achieved fabrication on 4- and 6-in. wafers and used deep ultraviolet lithography and smooth and uniform etching to realize 0.27 dB/cm optical propagation loss on wafer scale, allowing efficient light guiding.

According to Kevin Luke, the research paper lead author and head of manufacturing at HyperLight, the devices are not limited to high-end applications, but can be mass produced at competitive price points. The technology, he said, will have a broad impact on performance and cost-sensitive technologies such as data center networking, 5G radio communication systems, and automotive lidar.

Lithium niobate has significant performance advantages over silicon for use in PICs, though manufacturing at larger scales has proved challenging. Silicon has been able to leverage existing fabrication infrastructure from the CMOS transistor industry, though this research shows that lithium niobate can use the same fabrication tools.

“Such PICs will allow for unprecedented control of temporal and spectral properties of photons, which is essential for realization of photonic quantum computers,” said Marko Loncar, co-founder and chief sciences adviser at HyperLight and a professor at Harvard University.