用于水下声光通信的外差式激光多普勒振动计

Heterodyne Laser Doppler Vibrometer for Underwater Acousto-Optic Communication

基于外差激光多普勒原理,设计并实现了一套光纤结构的外差式激光多普勒振动计(LDV)。在消声水池,对该系统的探测灵敏度、上行声光通信速率以及水面波浪的影响进行了测试实验。实验结果表明,系统最小探测声压达105.6 dB/μPa;在平静水面,无误码情况下,声光通信速率可达5 kbit/s;在有小波浪的水面,导致部分探测信号丢失,采用扩频调制通信方式,无误码情况下,声光通信速率可达30 bit/s。

Base on the heterodyne laser Doppler theory, a heterodyne laser Doppler vibrometer（LDV） with fiber structure was designed and implemented . The sensitivity and communication rate of the system, and the influence from water surface wave were tested in anechoic tank. The experimental results show the smallest detectable sound press of 105. 6 dB/uPa. On hydrostatic water surface, the acousto-optic communication rate reaches 5 kbit/s without error; some signal is Dropped on hydrodynamic water surface, but using the spread-spectrum modulation, the aeousto-optic communication rate reaches 30 bit/s without error.