On January 22, 2025, a research team led by Ou Xin from the Shanghai Institute of Microsystem and Information Technology at the Chinese Academy of Sciences achieved a significant breakthrough in the field of electro-optic frequency comb chips. Collaborating with Professor Gabriel Santamaria Botello from the University of Colorado, USA, and Professor Tobias J. Kippenberg from the École Polytechnique Fédérale de Lausanne, Switzerland, the team utilized lithium tantalate single-crystal thin films on insulators for their study. The groundbreaking findings, titled "Ultrabroadband Integrated Electro-Optic Frequency Comb in Lithium Tantalate," have been published in the prestigious international journal Nature.

This research addresses long-standing issues in traditional electro-optic materials, such as excessive birefringence and low energy efficiency in microwave circuit design. The team successfully developed an integrated electro-optic frequency comb with a spectral span exceeding 450 nanometers and featuring over 2000 spectral lines. Notably, the device size has been minimized to within 1 square centimeter, the spectral width has been expanded fourfold, and the efficiency has been enhanced by a factor of 16.

Furthermore, the research demonstrates the key-on and wide-range stable tunable performance of the lithium tantalate electro-optic frequency comb. This advancement provides a robust platform for the next generation of chip-scale multi-source coherent communication, chip-scale spectroscopy, and ultra-low noise millimeter-wave synthesis, heralding a new era in these cutting-edge technologies.