26th Australian Institute of Physics Congress and the Australian and New Zealand Conference on Optics and Photonics

Micro-transfer printing thin-film lithium niobate onto SiN photonic chips

Not scheduled

20m

Belinda Hutchinson Building (The University of Sydney )

Poster ANZOS | Photonics and Optics (ANZCOP)

Description

Micro-transfer printing thin-film lithium niobate onto SiN photonic chips

Photonic integrated circuits (PICs) are poised to drive the intelligent future, much like microelectronics have powered the information era over the past few decades. This potential was underscored by Nvidia's March 2025 announcement of Spectrum-X Photonics, a co-packaged optics networking switch designed to scale AI factories to millions of GPUs. This product offers 3.5 times energy savings and 10 times greater resilience in AI factories, with silicon photonic PICs serving as the core enabling technology.
Even though, silicon photonic PICs still suffer from high optical waveguide propagation loss and high-power consumption in electro-optical modulators. Silicon nitride (SiN) can reduce propagation loss by over 100 times compared to silicon, but its low electro-optical coefficient limits the performance of its modulators. Emerging thin-film lithium niobate on insulator (LNOI) technology inherits the advantages of mature commercial electro-optical modulators, offering both low propagation loss and high-performance modulation. However, LNOI's high cost and fabrication challenges hinder widespread adoption. To address these limitations, we have developed a SiN-loaded LNOI platform at RMIT to avoid direct lithium niobate etching. This platform has enabled the demonstration of key optical components for telecommunications and microwave photonics1-3.
Our current SiN-loaded LNOI platform deposits silicon nitride onto LNOI wafers, but lithium niobate is required only for specific components, such as electro-optical modulators and frequency-mixing devices. This results in significant material waste, as LNOI wafers are 10 times more expensive than SiN. By selectively transferring small thin-film lithium niobate pieces onto prefabricated SiN PICs, this project will drastically reduce costs without compromising device performance. This work will pave the way for hybrid integration of various functional building blocks—such as lasers, detectors, and gain media—onto a mature, cost-effective SiN platform for real-world applications.