AUTHOR=Wang Ke , Li Jing , Dai Fan , Wang Mengshuai , Wang Chuanhang , Wang Qiang , Tu Chenghou , Li Yongnan , Wang Hui-Tian 

TITLE=Kerr nonlinearity-assisted quadratic microcomb

JOURNAL=Frontiers in Physics

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2022.1026618

DOI=10.3389/fphy.2022.1026618

ISSN=2296-424X

ABSTRACT=Generation of nonlinear frequency combs in χ(3) optical microresonators attracted tremendous research interest during the last decade. Recently realization of microcomb owing to χ(2) optical nonlinearity in the microresonator promises new breakthroughs and is a big scientific challenge. Moreover, it is of high scientific interest that the presence of both second- and third-order nonlinearities results in complex cavity dynamics. Especially the role of χ(3) nonlinearity in the generation of the quadratic microcomb is still far from being well-understood. Here, we demonstrate the interaction between the second- and third-order nonlinearity in the lithium niobate microresonator, which can provide new way of phase matching to control the mode locking condition and pulse number for the quadratic microcomb. Out results verify that the Kerr nonlinearity can benefit the quadratic microcomb. The principle can be further extended to other material platforms to provide more manipulation method for comb generation based on χ(2)  nonlinearity at mid-infrared.