In the Quantum Technology group, we are developing the foundations for a new generation of compact, powerful and scalable photonic devices that will shape the future of quantum and classical photonic systems. Our focus is on integrated photonics in lithium niobate, in particular thin-film lithium niobate (TFLN) and traditional titanium-diffused waveguides.

We are building a modular toolbox of high-precision components that serve as building blocks for complex devices integrated on chips. These include TFLN waveguides with customised optical properties, periodically-poled TFLN structures for non-linear processes such as frequency doubling and parametric down conversion (PDC), and electro-optic modulators with high bandwidth and low switching voltages.

By combining materials Science, micro- and nanofabrication and optical system integration, we work at the interface between basic research and technological implementation - with the aim of making quantum and photonic systems more efficient, smaller and more usable.

Periodic poling is the basic requirement for efficient, non-linear processes in TFLN components. We realise homogeneous, continuous periodic poling over large wafer areas to enable efficient and high-purity single-photon sources as well as non-linear processes such as parametric amplification and frequency conversion. By developing innovative segmented finger electrodes, we optimise the poling accuracy and homogeneity [2], which significantly improves the stability and performance of quantum light sources.

We draw on over 40 years of experience in the development and optimisation of titanium-diffused waveguides, which are now regarded as an absolutely mature and highly reliable technology. These waveguides offer excellent optical properties, extremely low optical losses, are ideal for the generation of entangled photon pairs and the implementation of complex quantum optical circuits. Their high stability and reproducibility make them an established building block in quantum photonics.