低频水下声信号调制下衍射光场的分布

摘要

建立了一个简单可行的光学系统用于探测低频水下声信号。水下声信号产生的低频声波通过水介质传到液体表面产生表面波，激光束入射到液面时，在光屏上观察到了清晰、稳定的衍射图样，发现在低频水下声信号的调制下衍射光场的分布具有明显的不对称性。实验中得到了衍射图样光斑光强与位置的分布，理论分析发现，结果与实验所观察到的现象是很吻合的。结果表明，在低频水下声信号调制下衍射光场的分布是非对称分布的。%A measurement system is developed to detect the low-frequency underwater acoustic signal.The clear and high stable diffraction pattern is observed experimentally when the laser beam illuminates on the liquid surface which is modulated by the underwater acoustic signal, the diffraction fringes is asymmetric distribution.The asymmetry of the position and intensity of the diffraction spot were explained with the laser oblique incidence.The experiment is consistent with the theory.The results show that it is asymmetric distribution of the diffraction light field which is modulated by low-frequency underwater acoustic signal.