无衍射光束自重建的两种方法

Two Methods of Generating the Self-Reconstruction of the Non-Diffracting Beams

利用透镜聚焦法与障碍物重建法实现无衍射光束的自重建,对无衍射光束自重建的传播特性及其光强分布变化进行数值模拟.结果表明,利用聚焦透镜与障碍物都可以使无衍射光重建,但重建后的无衍射光束的中心光斑的光强都较重建前弱,且光斑半径较大,亮环也较稀疏.利用聚焦透镜实现重建,只要加另一透镜进行矫正,便可得到光束质量非常好的无衍射光,且无衍射距离较重建前更长.利用Bessel光经障碍物重建,无需借助额外的实验装置,便可方便地对粒子进行捕获,而且重建后的无衍射光经过障碍物可再重建.

The reconstruction property of the non-diffracting beam generated by using the axicon-lens system and by passing through an opaque obstacle was studied. The propagation property and the optical intensity distribution of the reconstructed Bessel beam were simulated by the computer. It is shown that the non-diffracting beam can be reconstructed by the forementioned two methods, however, the reconstructed beam has a weaker central intensity, a larger spot size and fewer bright rings than the original beam. By lens focusing method, high quality non-diffracting beams with a longer non- diffracting distance has been obtained with a rectifying lens. However, no additional equipment is needed by using the ob- struction self-reconstruction method to reconstruct the non-diffracting beam and the reconstructed beam can be used to trap the particles. Moreover, it could be reconstructed again when it passes another obstacles.