双轴棱锥产生长距离近似无衍射光的新技术

提出了一种利用会聚透镜、轴棱锥等简单光学元件产生长距离近似无衍射光的新技术. 分别利用几何光学和衍射理论分析了该方法产生长距离近似无衍射光束的原理, 通过软件模拟了长距离近似无衍射光束的形成过程,得出了该光束在不同距离处的横向光强分布. 模拟结果显示该光束在较长距离处的横向光强分布满足Bessel分布. 从实验上获得了传播距离长达80 m、中心光斑发散角约为0.12 mrad的近似无衍射光束, 相比于国外学者最近的研究成果(Belyi et al. 2010 Opt. Exp. 18 1966)将传播距离延长了50多米,而光束发散角压缩了22倍.实验中, 对光束沿光轴传播时在不同距离处的光斑进行了拍摄,所得实验结果与理论分析基本符合.

A new technique for generating non-diffracting beam with long propagation distance using two axicons

A new technique for generating quasi non-diffracting beam with long propagation distance by using simple optical elements including the convergent lens and axicons is proposed. The theory of generating such a beam is studied with geometrical optics and diffraction theory. The formation process of the beam is simulated, and the transverse intensity distributions at various distances are obtained. The simulation results show that the transverse intensity distribution at long-distance accords with Bessel distribution. A comparison between the quasi non-diffracting beam, which is obtained by our experiment, and that in the literature (Belyi et al. 2010 Opt. Exp. 18 1966) shows that its propagation distance is more than 50 m longer, and the beam divergence angle is compressed by 22 times. In the experiment, the beam patterns are captured at different propagation positions, and the obtained results are in good agreement with the theoretical analyses.