Propagation properties of partially coherent power-exponent-phase vortex beam

Kang Chen,Zhi-Yuan Ma,You-You Hu,Jian-Tai Dou,Ming-Ming Zhang

doi:10.7498/aps.71.20211411

Abstract

In this work, the propagation properties of partially coherent power-exponent-phase vortex beam are studied. Firstly, the propagation model of partially coherent power-exponent-phase vortex beam is established. Then, the propagation properties of partially coherent power-exponent-phase vortex beams in free space and ABCD optical system are simulated. The results show that when power-exponent-phase vortex beams propagate in free space, the topological charge, power order and coherence length have a great influence on the distribution of light intensity, and the area of light spot gradually increases with the increase of propagation distance. When the beam propagates in a focusing system, the changes of topological charge and power order will affect the light intensity distribution, while the coherence length has little effect on the overall intensity distribution of the beam, but only the quality of the spot. The research results of this work reveal the propagation properties of partially coherent power-exponent-phase vortex beam, which will lay a theoretical foundation for its applications in optical capture and other fields, and has important significance in promoting the theory and applications of new light field regulation.

Highlights

The results show that when power-exponent-phase vortex beams propagate in free space, the topological charge, power order and coherence length have a great influence on the distribution of light intensity, and the area of light spot gradually increases with the increase of propagation distance
研究结果表明, 当部分相干幂指数相位涡旋光束在自由空间和聚焦系统中传输时, 拓扑荷数 l 都决定了光束传播截面的大小, 及其所拥有暗核的数量, 并且随着 n 的增大, 暗核逐渐消失; 同时随着 l 和 n 值越大时, 能量更集中于强度点, 聚焦的效果也越好

Summary

Introduction

而幂指数相位涡旋 (Power-exponent-phase vortex, PEPV) 光束是一种新型的涡旋光束 [7], 其相位 exp[i2lπ (φ/2π )n]是由幂指数 n 与拓扑荷数 l 来决定的. 当幂指数 n = 1时, 幂指数相位涡旋光束退化成传统的 exp(ilφ) 涡旋光束. 如图 1 所示, 分别为拓扑荷数 l = 4 的涡旋光束和拓扑荷数 l = 4、幂指数 n = 2 的幂指数相位涡旋光束在源平面上的与传统的相干光束相比, 部分相干光束 [10,11] 展现出了一些新颖的物理特性—降低光束散斑效应、减小经过随机介质的光束闪烁、漂移和自修复等, 在“鬼”成像 [12]、相干衍射成像 [13]、粒子捕获 [14] 等方面都具有广泛的应用前景. 图 1 (a), (c) 拓扑荷数 l=4 的涡旋光束和 (b), (d) 拓扑荷数 l = 4 及幂指数 n = 2 的幂指数相位涡旋光束在源平面上的相位和强度分布 Fig. 1.

Results

Conclusion