Open AccessHigh-order optical vortex position detection using a Shack-Hartmann wavefront sensor
Author(s) -
Jia Luo,
Hongxin Huang,
Yoshinori Matsui,
Haruyoshi Toyoda,
Takashi Inoue,
Jian Bai
Publication year - 2015
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.008706
Subject(s) - optics , physics , wavefront , position (finance) , wavefront sensor , optical vortex , phase (matter) , intensity (physics) , beam (structure) , adaptive optics , vortex , measure (data warehouse) , computer science , finance , quantum mechanics , database , economics , thermodynamics
Optical vortex (OV) beams have null-intensity singular points, and the intensities in the region surrounding the singular point are quite low. This low intensity region influences the position detection accuracy of phase singular point, especially for high-order OV beam. In this paper, we propose a new method for solving this problem, called the phase-slope-combining correlation matching method. A Shack-Hartmann wavefront sensor (SH-WFS) is used to measure phase slope vectors at lenslet positions of the SH-WFS. Several phase slope vectors are combined into one to reduce the influence of low-intensity regions around the singular point, and the combined phase slope vectors are used to determine the OV position with the aid of correlation matching with a pre-calculated database. Experimental results showed that the proposed method works with high accuracy, even when detecting an OV beam with a topological charge larger than six. The estimated precision was about 0.15 in units of lenslet size when detecting an OV beam with a topological charge of up to 20.