Affiliation:
1. Suzhou City University
2. Soochow University
3. Shandong Normal University
Abstract
We demonstrate that the spiral spectrum (also known as orbital angular momentum spectrum) of a Laguerre-Gaussian (LG) beam with topological charge (TC) l is asymmetrically broadened propagating through moderate-to-strong atmospheric turbulence, even the statistics of turbulence is isotropic. This phenomenon is quite different from that predicted in weak turbulence where the spiral spectrum of a disturbed LG beam is symmetric with respect to its TC number l. An explicit analytical expression of the spiral spectrum of the LG beam with l = 1 is derived based on the extend Huygens-Fresnel integral and quadratic approximation, which is used to illustrate the transition scenarios of the spiral spectrum from symmetry to asymmetry in weak-to-strong turbulence. The physical mechanism for the asymmetric spiral spectrum in moderate-to-strong turbulence is thoroughly discussed. Our results are confirmed by the multi-phase screen numerical simulations and are consistent with the experimental results reported in Phys. Rev. A 105, 053513 (2022)10.1103/PhysRevA.105.053513 and Opt. Lett. 38, 4062 (2013)10.1364/OL.38.004062.
Funder
National Key Research and Development Program of China
National Natural Science Foundation of China
Local Science and Technology Development Project of the Central Government
China Postdoctoral Science Foundation
Natural Science Foundation of Shandong Province
Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications
Subject
Atomic and Molecular Physics, and Optics