摘要
研究了任意形状凸粗糙物体对高斯光束的相干散射特性。由平面波谱展开法推导出粗糙面高斯波束散射场表达式,并根据物理光学近似和稳相法原理得到相干散射截面的理论公式。与平面波解不同的是,在公式中引入了波束因子这一表征波束作用的重要参量,该参量与束腰半径、束腰中心与物体中心距离和物体照射面积以及入射、散射方向有关。最后数值计算了1.06μm激光波束对粗糙球的散射,分析了波束因子,介电常量和极化状态对红外激光相干散射截面的影响,重点讨论了波束因子的变化规律。分析表明,当波束半径远大于物体尺寸时,波束入射的结果可退化到平面波情况。
The coherent scattering of Gaussian beam by arbitrarily shaped convex dielectric object with rough surface is investigated. Based on the plane wave spectrum method, the scattered field of Gaussian beam from rough object is derived and the formula for calculating the coherent scattering cross section is obtained using the physical optics approximation and the stationary phase method. Compared with the result of plane wave, additional beam factor represents the effect of Gaussian beam, which is related to beam waist size, distance from beam waist to object center and the illuminated area on object, together with the incident or scattering angles. Finally the 1.06 μm laser beam scattering from rough sphere is numerically computed, and the influence of the beam factor, permittivity and polarization on coherent LRCS is analyzed. It is shown that the results of Gaussian beam will approach that of plane wave when the beam radius is much larger than the size of object.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2005年第1期115-120,共6页
Acta Optica Sinica
基金
国家自然科学基金(60371020)资助课题。
