Miniaturized GaN-Based Optical Hydrophones for Underwater Low-Frequency Acoustic Detection

作者：Liushu Pan, Shengquan Li, Jian Chen, Ming‐Cheng Luo, Long Zhang, Linbojie Huang, Kwai Hei Li, Xinke Tang · 发表于：IEEE Photonics Technology Letters · 年份：2024 · DOI：10.1109/lpt.2024.3454151 · 被引用次数：3 · 研究领域：Acoustic Wave Resonator Technologies、Underwater Vehicles and Communication Systems、Analytical Chemistry and Sensors

In this letter, the fabrication and characterization of a miniaturized optical hydrophone for detecting underwater acoustic signals is demonstrated. A light emitter and detector are fabricated on a GaN-based device at chip scale through the monolithic integration approach. By incorporating a deformable PDMS film embedded with TiO2 nanoparticles, the sound vibration can be effectively converted into photocurrent changes. The millimeter-sized hydrophone can detect hydro-acoustic signals ranging from 0.1 Hz to 250 Hz, with an optimum sensitivity of about$2.3\times 10 ^{-14}$A/$\mu $Pa at around 48 Hz and a minimum detectable pressure of about 4 Pa. It is capable of distinguishing waves originating from two distinct acoustic sources with a frequency difference as low as 0.2 Hz. This cost-effective, chip-scale design with high stability holds great potential for a variety of applications that necessitate identifying low-frequency acoustic signals in underwater environments.