The analytical expression of the average intensity of an off-axis Gaussian Schell-model beam during propagation is derived and such focused beam's ability to capture particles is analyzed. It is found that the spectral density along propagation direction in strongly nonlocal nonlinear media (SNNM), and in SNNM under off-waist incident condition, both presents a periodical distribution. Further, the propagation trajectory of the beam center is quantitatively analyzed. Results show that the trajectory of the beam center upon propagation is a sinusoidal curve. This focused beam is helpful to capture high-index particles. In addition, the linear factor and coherent length also have an effect on the distribution of radiation force.

中文翻译：

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离轴高斯谢尔模型光束的统计特性及应用研究

导出了离轴高斯谢尔模型光束在传播过程中平均强度的解析表达式，并分析了这种聚焦光束捕获粒子的能力。发现在强非局部非线性介质（SNNM）和非腰部入射条件下的SNNM沿传播方向的谱密度均呈现周期性分布。此外，对光束中心的传播轨迹进行了定量分析。结果表明，传播时光束中心的轨迹是一条正弦曲线。这种聚焦光束有助于捕获高指数粒子。此外，线性因素和相干长度对辐射力的分布也有影响。