Focused vortex beam generator suitable for optical fiber spanners in a complex liquid environment

We experimentally demonstrated an all-fiber focused vortex beam (FVB) generator which was prepared by milling a spiral zone plate (SZP) on the Au-coated end face of a hybrid fiber by focused ion beam (FIB). In this generator, the fundamental modes propagating in the hybrid fiber are focused while be...

Full description

Saved in:
Bibliographic Details
Published in:Optics letters 2022-12, Vol.47 (24), p.6476-6479
Main Authors: Bai, Zhiyong, Wu, Luping, Liu, Rui, Yu, Jian, Ma, Dingbang, Chen, Zikai, Ran, Jianjun, Wang, Ying, Liao, Changrui, Wang, Yiping
Format: Article
Language:English
Subjects:
Angular momentum
Diameters
Electron beams
Generators
Gold coatings
Ion beams
Optical fibers
Propagation modes
Topology
Zone plates
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We experimentally demonstrated an all-fiber focused vortex beam (FVB) generator which was prepared by milling a spiral zone plate (SZP) on the Au-coated end face of a hybrid fiber by focused ion beam (FIB). In this generator, the fundamental modes propagating in the hybrid fiber are focused while being modulated into high-order orbital angular momentum (OAM) mode by the SZP at the end face. The focus length and topological charge were designed and then were both theoretically and experimentally verified. The results show that, the obtained characteristics of the FVB agree with the designed ones. The measured diameters of the focal spots are 2.2 µm, 4.4 µm, and 5.2 µm for the FVB with the topological charge of 0, 1, and 2, respectively. The simulated results show that the proposed FVB generators can maintain good focusing characteristics in different liquids, so it is a good candidate for optical fiber spanner use in a complex liquid environment. Moreover, the processing efficiency of the proposed FVB generators is nearly ten times higher than that of the previously reported ones due to the Au-coated film.
ISSN:0146-9592
1539-4794
DOI:10.1364/OL.465949