Harnessing sub-comb dynamics in a graphene-sensitized microresonator for gas detection  

作　　者：Yupei Liang Mingyu Liu Fan Tang Yanhong Guo Hao Zhang Shihan Liu Yanping Yang Guangming Zhao Teng Tan Baicheng Yao 

机构地区：[1]Key Laboratory of Optical Fiber Sensing and Communications(Ministry of Education),University of Electronic Science and Technology of China,Chengdu 611731,China [2]Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China [3]Engineering Center of Integrated Optoelectronic&Radio Meta-Chips,University of Electronic Science and Technology,Chengdu 611731,China

出　　处：《Frontiers of Optoelectronics》2024年第2期11-21,共11页光电子前沿（英文版）

基　　金：support from the National Key Research and Development Program of China(Nos.2023YFB2805600,2021YFB2800602,2023YFB2806200);the National Natural Science Foundation of China(Grant Nos.U2130106 and 62305050);the National Postdoctoral Innovation Talent Support Program of China(No.BX20220056);Industrial Key Project of China Southern Power Grid(No.CG2100022001608777).

摘　　要：Since their inception, frequency combs generated in microresonators, known as microcombs, have sparked significant scientific interests. Among the various applications leveraging microcombs, soliton microcombs are often preferred due to their inherent mode-locking capability. However, this choice introduces additional system complexity because an initialization process is required. Meanwhile, despite the theoretical understanding of the dynamics of other comb states, their practical potential, particularly in applications like sensing where simplicity is valued, remains largely untapped. Here, we demonstrate controllable generation of sub-combs that bypasses the need for accessing bistable regime. And in a graphene-sensitized microresonator, the sub-comb heterodynes produce stable, accurate microwave signals for high-precision gas detection. By exploring the formation dynamics of sub-combs, we achieved 2 MHz harmonic comb-to-comb beat notes with a signal-to-noise ratio (SNR) greater than 50 dB and phase noise as low as – 82 dBc/Hz at 1 MHz offset. The graphene sensitization on the intracavity probes results in exceptional frequency responsiveness to the adsorption of gas molecules on the graphene of microcavity surface, enabling detect limits down to the parts per billion (ppb) level. This synergy between graphene and sub-comb formation dynamics in a microcavity structure showcases the feasibility of utilizing microcombs in an incoherent state prior to soliton locking. It may mark a significant step toward the development of easy-to-operate, systemically simple, compact, and high-performance photonic sensors.

关 键 词：MICRORESONATOR Optical frequency comb GRAPHENE Gas sensing 

分 类 号：TN751.2[电子电信—电路与系统]