P6: Integrated Photonics for Scalable Quantum Computers

Most quantum computing architectures in the future require highly integrated and precisely aligned photonic structures that are optimized towards the seamless integration with qubit operation. Entangled light can be generated in optical cavities, while interferometric coupling structures allow for the manipulation and redistribution of quantum states. The required wavelength range spans from UV to NIR, imposing significant technological demands on the material selection, component design, manufacturing, and fabrication tolerances of integrated optical components. The goal of this project is to research the fabrication and characterization of scalable photonic components and architectures for signal generation, distribution, manipulation, detection and processing on wafers and microchips.

P7: System Integration for Low-Loss Photonic Couplings

Interferometric quantum gates and directed laser beams for the control and manipulation of qubits necessitate adapted system solutions for low-loss optical couplers as interfaces to quantum computer hardware. Depending on requirements, these interfaces can be implemented in free space, via optical fibers or with special chip-to-chip connections. In this project, manufacturing and assembly techniques as well as packaging concepts are investigated. Furthermore, wafer-scale fabrication technologies and maskless laser direct writing techniques are explored to improve the scalability and effectiveness of the coupling systems, with a focus on low-loss fiber-chip interfaces in optical thin films and embedded substrates.

Technological challenges investigated in P6 and P7

• Development of an integrated optical waveguide platform and testing of the platform by employing key building blocks for quantum applications.
• Design, simulation and fabrication of polymer-based low loss fiber to chip connections.
• Construction of opto-electronic measurement setups and characterization of design variations in manufactured components.
• Static and dynamic tuning and trimming methods for component functionality adjustments.
• Design, realization and test of electrical and optical assemblies for quantum applications.
• Design and Realization of spot-size converters and light focusing structures in thin films or the bulk of the substrate.

For interested students that would like to contribute to a project with design, simulation, technology and characterization at the leading edge of integrated photonic systems, please contact us. Whether for a research project or a master's thesis, you will be part of an enthusiastic team and together with us build the future of quantum silicon photonics.