2024 Hermann Anton Haus Lecture

Building 36, 428

High-Q PhotonicsKerry Vahala Professor of Applied Physics, Caltech Jenkins Chair in Information Science and TechnologyHigh-Q microresonators in the form of rings or disks provide access to nonlinear optical phenomena at milli-Watt power levels. And the resulting device functions, now in miniature form, are paving the way to compact (and even fully integrated) optical systems for sensing, metrology, spectroscopy, microwave generation, time keeping, and data transmission. Once discrete and reliant upon specialized processing techniques for optical loss reduction, high-Q microresonators are today planar, capable of integration, and in some cases fabricated on CMOS foundry lines. After a brief overview of their history and early nonlinear optical demonstrations, I will focus on frequency microcombs with an overview of system demonstrations as well as the recent integration of microcombs with pump laser diodes. I will also describe progress towards a compact, high-performance microwave signal source based upon 2-point optical frequency division using microcombs. In the chip-based system, a microcomb is combined with two, narrow linewidth semiconductor lasers to transfer frequency stability from a compact optical reference cavity into an electrical microwave signal. The performance of all sub systems and status of the overall system performance is provided.