利用差动激光多普勒探测法，研究了能够探测尾流中气泡和湍流分布的光学诊断方法。实验研究了模拟尾流场中运动气泡及湍流的后向散射光的多普勒频移谱特性。采用差动相干探测法获得了模拟尾流场的流速，测量值与实际流速误差小于1.5％。实验结果表明：相干光束夹角对散射光频移量具有明显影响，散射光多普勒频移量随两相干光夹角的增大而增大；气泡运动引起的频移主要集中在低频端，为一宽带谱；并且频移谱的宽度随气泡数密度的增大而增大。频谱的这一特征可作为舰船尾流识别的判据之一。

The optical method of differential laser Doppler for the ship wake detection was studied. The characteristics of the backscattering light for the bubble and turbulence were experimentally studied. The velocity of the ship wake field was obtained by the laser differential Doppler method, which is in coincidence with the actual value, and the relative error is less than 1.5%. The experimental results show that the angle between two coherent beams has obvious effects on the frequency shift. And the frequency shift increases as the angle increases. The frequency shift spectra for the bubble are characterized by a universal profile and at the low frequency end. The full width at half peak of the profile becomes larger as the field intensity increases, which can be seen as a criterion of the wake recognition.