Compact Comb Lights the Way for Next-gen Photonics

(EPFL, January 29, 2025)

EPFL researchers, led by Prof. Tobias Jan Kippenberg, have developed an electro-optic frequency comb generator that extends its spectral coverage to an impressive 450 nm, featuring over 2000 comb lines. They achieved this by using a novel "integrated triply resonant" design that synchronizes two optical fields with one microwave field, drastically reducing the microwave power needed by nearly 20 times. This was possible through a co-designed system that combines monolithic microwave circuits with photonic components on lithium tantalate photonics integrated circuits, improving microwave confinement and energy efficiency. This innovation paves the way for compact, durable devices with wide-ranging applications, from precise laser ranging in robotics to accurate gas sensing for environmental monitoring. Its ultra-broadband reach and stable performance not only make it easier to use but also expand its applications in the field, representing a significant advancement in the integration of microwave and photonic engineering. By harnessing the unique properties of lithium tantalate, EPFL's work opens new possibilities for future photonics technology devices.