传播轴 meaning in English

propagation axis

In the experiment , we use the he - ne laser and the semiconductor laser as the source , record the bessel beam patterns behind the axicon by using a digital camera and a microscope , measure the radius of the bessel beam central spot by film - scanning and measure the effect of both the radius of the aperture and the open angle of the axicon on the maximum non - diffraction distance . the experiments show that a specific propagating range has constant power and the beam has a bessel - like distribution in this range . the results agree with the beam corresponding to a diffraction free beam
同时我们还采用胶片扫描的方法测量了无衍射光束的中心光斑尺寸,测量了不同光阑孔径和不同棱角情况下的最大无衍射距离和传播轴附近横截面内微小光孔中的光强,实验结果显示当激光光束经过轴棱锥转换后有一段距离功率变化很小,且分布近似贝塞尔分布,符合无衍射光束的特性;经过聚焦后,呈现三维分布中空的光束bottlebeam ,实验结果与理论分析基本吻合。