AUTHOR=Wang Wuyue , Yu Yu , Bai Zhenxu , Li Yunfei , Wang Gong , Li Kai , Song Changyu , Wang Zhiyong , Li Sensen , Li Yuhai , Liu Tongyu , Yan Xiusheng , Wang Yulei , Lu Zhiwei TITLE=A Theoretical Study of Tunable Brillouin Lasers Based on a Diamond Suspended Waveguide JOURNAL=Frontiers in Physics VOLUME=Volume 10 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2022.913774 DOI=10.3389/fphy.2022.913774 ISSN=2296-424X ABSTRACT=A new type of hybrid waveguide structure is designed, which realizes independent control of phonon mode and optomechanical driving force, thereby generating customizable Brillouin coupling over a very wide bandwidth. The Brillouin gain reached 4400 W-1m-1, and the phonon nonlinear tunability from 1 - 95 GHz was realized. This hybrid waveguide width tuning scheme can realize photon-phonon conversion based on the Brillouin nonlinear effect and can guide and manipulate the phonons emitted by Brillouin on the chip. Therefore, this technique provides the opportunity to generate microwave sources using the on-chip Brillouin photoacoustic coupling mechanism new possibility.