On-chip dual-microcomb based fiber-optic acoustic mapper

Abstract Sense of hearing is a fairly basic but extraordinary feature in nature. It involves a complicated interplay of multi-dimensional signal detection, transmission, and analysis to fully accomplish acoustic detection, orientation, localization and recognition. Conventional design of a listening system typically necessitates numerous hardware components and intricate software interactions. Here, by assembling stabilized dual-microcombs, passive optical elements, optoelectronic photodetectors, electronic processors all-on-chip along with a fiber optic microphone array, we present an integrated optic-acoustic sensing and localization system that demonstrates coherent parallelism and compact integration. Our study establishes a paradigm in which an integrated soliton microcomb can simultaneously drive and demodulate networking sensors, thus overcoming the technological gaps between silicon-based photonics and fiber optic sensing technology. Utilizing two microcomb chips as the core, we boast sensitive optical acoustic detection, precise acoustic localization, and swift acoustic tracing capabilities together. Leveraging the unique advantages of soliton microcombs especially low noise and multi-channel outputs, we achieve a minimum detectable acoustic pressure of 0.79 μPa/Hz^(1/2) and a localization error of less than 1 cm. We further demonstrate its efficacy by detecting, tracking and identifying different targets such as a small drone in a field setting. Such a fusion of dual-comb technology and sensor-networking scheme could be a significant step towards the design of future listening systems.