尾流后向散射光功率衰减特性研究

依据Mie理论光散射在0°和180°有明显增强的结论，应用自行设计的模拟尾流后向散射光功率实验系统在632.8 nm He-Ne激光器直接照明和扩束后照明两种条件下，对模拟尾流后向散射光功率衰减特性进行了研究.结果表明,用后向散射光功率进行探测时，考虑到散射光在水中传播的衰减，对近距离分布的气泡，使用扩束光照明效果较好；对较远距离分布的气泡，使用细光束照明效果较好，其可探测的距离要比扩束光远.

Study of Attenuation Characteristic of Ship Wake′s Backward Scattered Light Based on the Detection of Optical Power

According to the Mie scattering theory,the backward light scattering power of air bubble appears as clear enhancement near 180° in the condition that the air bubbles are not relevant to each other.The experiment was done with the simulative ship wake. The attenuation characteristic of air bubbles' backward scattered light power was studied with 632.8 nm laser illumination in two conditions-slim beam illumination and expanded beam illumination. The experiment results indicate that considering the attenuation of light intensity as backward scattered light propagating in the water,expanded beam illumination has advantage when air bubbles is nearer and slim beam illumination is adapt to detect farther bubbles.