SYNOX
Symmetry-Driven Nonlinear Optics in Hexagonal Polytype Semiconductors
Supervisor: Charles RENARD | Employer: Universté Paris-Saclay | 3i dimension: international 📥 SYNOX
Contact: charles.renard@universite-paris-saclay.fr; laetitia.vincent@cnrs.frAbstract: This project explores crystal-phase control to engineer material properties and unlock new functionalities. Building on a patented breakthrough enabling the growth of metastable hexagonal semiconductor thin films, we will investigate their nonlinear optical behaviour. The anisotropic hexagonal symmetry is expected to provide strong χ(2) and intrinsic birefringence, enhancing SHG and SPDC for applications in frequency conversion, optical modulation, sensing and quantum photonics. As a first demonstrator, the SYNOX project aims to develop disruptive sources of correlated photon pairs via SPDC in subwavelength AlGaAs-hex films, a key enabler for secure quantum communication. Our vision is to design and integrate miniaturized nonlinear optical devices, paving the way toward fully integrated and scalable on-chip quantum light sources for practical quantum technologies.
Project Objectives
The success of the SYNOX project relies on the complementary expertise on material growth and optical characterisation. A multidisciplinary consortium with complementary expertise has therefore been established to cover the full value chain from material synthesis to photonic device demonstration. SEEDs team brings unique expertise in the synthesis of metastable semiconductors while the synergy with nonlinear optical characterization (SHG and SPDC) experts ensures that the PhD candidate will receive interdisciplinary training while developing strong experimental and analytical skills. The ETH Zurich group is internationally recognized for its expertise in nonlinear optics and integrated photonics, and will lead the demonstration of SPDC in ultrathin AlGaAs-hex films as well as the proof-of-principle generation of entangled photon pairs. This project represents a unique opportunity to strengthen a newly forming international consortium, as the ETH Zurich co-supervisor brings indispensable and complementary expertise, enhancing both the scientific scope and the collaborative dimension of the project. Additionally, the collaboration with HORIBA will support the upgrade of the polarized SHG setup and leverage their expertise in these advanced measurements, further reinforcing the project's experimental capabilities and impact. The project aims to provide the scientific foundation for a future EIC Pathfinder project, targeting potential applications of this new material in nonlinear optics.
Host Laboratory: C2N 3i Host Laboratory: ETH Zurich
Specific skills and requirements
Pre-requisite: TO BE UPDATED - REFER TO PDF
Advantageous: TO BE UPDATED - REFER TO PDF
Biographies
Thesis Director Short Bio: C. Renard: Coming soon
3i Co-supervisor Short Bio: Since 2025 Rachel Grange appointed Full Professor of Photonics at ETH Zurich. She has been Associate Professor and Assistant Professor in the field of integrated optics and nonlinear nanophotonics in the Department of Physics at ETH Zurich since 2015. From 2011 to 2014, she was junior group leader at the Friedrich Schiller University in Jena, Germany. Her research covers material investigations at the nanoscale, top-down and bottom-up fabricated nanostructures, mainly thin film lithium niobate and solution processed barium titanate for classical and quantum devices. Recently, she worked on integrated electro-optic spectrometers, on random quasi-phase matching phenomena in complex assemblies of nanocrystals, and parametric down conversion signals for quantum information processing. She is the coordinator of the main clean room facilities and the head of the physics department.
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