环状光束通过透镜的聚焦特性研究

Study on Focusing Properties of Annular Beams Through Circular Lens

给出了环状光束在柱坐标系下的一种描述模型,并利用广义衍射积分理论,推导出环状光束经过近轴ABCD光学系统的传输公式·在此基础上,通过数值模拟方法定量分析了环状光束的聚焦光强分布以及焦面处的桶中功率·研究结果表明,环状光束的聚焦特性与光束阶数以及系统菲涅耳数有关;环状光束在实际焦面和几何焦面上的桶中功率均随着遮拦比的增大而降低,而随着系统菲涅耳数的增大而增大·在实际工作中,通过合理地选取系统菲涅耳数和光束遮拦比可以有效地控制环状光束聚焦后的光束质量·

The model of the annular beams under the cylindrical coordinate system was proposed . According to the theory of generalized diffraction integration,the formula for the annular beams propagating through paraxial ABCD optical systems was derived. Using the method of numerical simulation, the focusing intensity distribution of annular beams and the power in the bucket （PIB） in the focal plane of annular beams were analyzed quantitatively. The numerical calculation results show that the focusing properties of the annular beams depend on the beam orders of the annular beams and the Fresnel number of the system. The powers in the bucket in the geometrical and real focal planes of annular beams decreases with the increasing obstruct ratio while increases with the increase of the Fresnel number of the system. In practical applications,the beam quality of the focused annular laser beams can be effectively controlled through the proper selection of Fresnel number and obstruct ratio.