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

• DOI: 10.1007/s12200-024-00115-5
• Publication Date: 2024-05-01T00:02:54Z
• Authors: Yupei Liang; Mingyu Liu; Fan Tang; Yanhong Guo; Hao Zhang; Shihan Liu; Yanping Yang; Guangming Zhao; Teng Tan; Baicheng Yao
• Keywords: Bistability

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