Per Lynggaard

This PhD project at DTU Electro focuses on electronic-photonic integration for scalable information processing, combining thin-film lithium niobate (TFLN) photonic circuits with custom CMOS chips . The research addresses a central challenge in modern computing and photonic hardware: how to move from isolated photonic devices to chip-scale systems that can be driven, stabilized, and controlled electronically at scale. The project EPIC develops 3D integration of photonic and CMOS chips through flip-chip bonding . The photonic side uses TFLN, a platform known for its transparency from the visible to the mid-infrared and its strong electro-optic effect, enabling fast modulation with low optical loss. The work builds on recent results from the group on photonic crystal cavities in TFLN, including ultracompact modulators and electrically controllable coupling to waveguides. You will contribute to the design, fabrication, and characterization of devices that integrate resonator-based photonic components with electronics for local control. A key scientific goal is to keep many fast modulators and resonators stable across a chip by combining photodetectors, feedback circuits, and drive electronics with the optical structures. The project spans co-design, fabrication in DTU Nanolab’s cleanroom, chip assembly, and high-speed electro-optic testing. The work is embedded in a collaborative research environment at DTU Electro, involving Professor Per Lynggaard’s CMOS design team, other PhD students, postdocs, and senior researchers. The project also connects with collaborators at Harvard University, whose work has significantly shaped the TFLN field. The student will engage in experimental, interdisciplinary research across photonics, electronics, and device integration, with opportunities to present results internationally. The scholarship is part of the EPIC project funded by the Independent Research Fund Denmark.