About the project
Combining low-loss optical routing with high-speed modulation requires complementary photonic materials. This project will integrate thin-film lithium niobate with silicon nitride to develop a scalable electro-optic platform. Research will address material integration, optical transitions and radio-frequency design for high-bandwidth devices and advanced photonic circuits.
Silicon nitride (SiN) provides low-loss passive photonic circuits, while thin-film lithium niobate (TFLN) offers a strong Pockels effect for high-speed electro-optic control. Integrating these capabilities requires simultaneous control of material interfaces, optical mode transfer and radio-frequency propagation.
This project aims to develop a heterogeneous TFLN-on-SiN platform for high-bandwidth electro-optic devices. The central research question is how integration processes and optical and electrode designs can be coordinated to achieve efficient modulation while preserving low-loss passive routing and fabrication tolerance.
The research will investigate bonding or transfer processes and develop optical transitions between SiN waveguides and TFLN device regions. Modelling and experimental characterisation will quantify transition loss and sensitivity to geometry, alignment and process variation.
High-speed modulators will provide the primary device demonstrator. Optical and radio-frequency simulations will guide electrode design, addressing electro-optic overlap, impedance matching, velocity matching and electrode loss. Fabricated devices will be assessed through measurements of modulation efficiency, insertion loss and electro-optic bandwidth. The validated platform will also provide a basis for investigating wavelength conversion or electro-optic frequency-comb generation.
The expected contribution is an experimentally validated integration process, high-bandwidth device designs providing at least 100GHz electro-optical bandwidth, and quantified fabrication tolerances. These outcomes will support reusable electro-optic building blocks for high-speed optical interconnects, microwave photonics and frequency-comb systems.
Comprehensive training will be provided in photonic and optical modelling using Ansys Lumerical, COMSOL Multiphysics and Zemax, alongside full equipment training in the University of Southampton’s cleanroom facilities. You'll also receive hands-on training in optical measurements and silicon photonic chip testing, including optical alignment, fibre-to-chip coupling and device characterisation. Together, these activities will develop the skills required to design, fabricate and experimentally validate integrated photonic devices.
The School of Optoelectronics (ORC) is committed to promoting equality, diversity inclusivity as demonstrated by our Athena SWAN award. We welcome all applicants regardless of their gender, ethnicity, disability, sexual orientation or age, and will give full consideration to applicants seeking flexible working patterns and those who have taken a career break. The University has a generous maternity policy, onsite childcare facilities, and offers a range of benefits to help ensure employees’ well-being and work-life balance. The University of Southampton is committed to sustainability and has been awarded the Platinum EcoAward.
