得出了在直接光强检测方式下表面微波的最小可探测幅度值，并且分析了 最小可探测幅度值分别和探测高度、接收孔径的关系。在直接光强检测方式下，针对水下声场形 成的表面微扰现象，通过建立探测系统的一维物理模型进行了理论推算。结论为：直接光强检测方式 下表面微波的最小可探测幅度值为0.4244mm。当表面微波幅度超过该值时，探测系统的灵敏度完 全满足对水下声场的实时监测要求。

In this paper, the minimum detectable amplitude of the microwave at water surface sensed by using a direct laser intensity detection method is derived and the relationships of this minimum detectable amplitude with detection height and receiving aperture are analyzed. According to the perturbation phenomenon formed by the underwater acoustic field at water surface in the direct laser intensity detection method, theoretical calculation is carried out by establishing the one-dimensional physical model of the detection system. It is concluded that the minimum detectable amplitude of the microwave at water surface is 0.4244mm when the direct laser intensity detection method is used. If the amplitude of the microwave at water surface is greater than 0.4244mm, the detection system can meet the real-time monitoring requirement of the underwater acoustic field completely.