基于部分相干光束的角谱表述和稳相法,研究了非传统空间关联结构对非傍轴部分相干光束的远场光强和发散角特性的影响,推导了非傍轴贝塞尔-高斯谢尔模(BGSM)光束经圆形光阑衍射后在远场的光强和发散角的解析表达式,利用该表达式数值计算了非傍轴BGSM光束的远场光强和发散角特性。结果表明,非傍轴BGSM光束与非傍轴高斯-谢尔模光束的远场光强及发散角特性不同,并且与光束在光源平面的空间关联结构、束腰半径、相干长度以及光阑半径密切相关。因此,调控光束的空间关联结构可以调控非傍轴部分相干光束的远场传输特性。

Based on the angular spectrum representation of partially coherent beams and the method of stationary phase, the far-field light intensity and divergence angle properties of nonparaxial partially coherent beams with nonconventional spatial correlation structure are studied. Analyticall expressions of the far-field light intensity and divergence angle of nonparaxial Bessel-Gaussian Schell-model (BGSM) beam diffracted by a circular aperture are derived. The properties of the far-field light intensity and divergence angle of the BGSM beam are illustrated numerically by the expressions. The results show that the far-field light intensity and divergence angle properties of the nonparaxial BGSM beam are obviously different from that of nonparaxial Gaussian Schell-model beam, and are closely related to the spatial correlation structure, beam waist width, coherence length and aperture radius in light source plane of the beams. Modulating the spatial correlation structure of the beam provides a novel way to modulate the propagation properties of nonparaxial partially coherent beam in the far-field.