Calibration of Measurement of Multiple Polarization Singularities

Abstract

In this paper, we propose a method used to measure the polarization state of a field with multiple polarization singularities (PSs), such as an array of PSs and PSs in vector speckle. A checkerboard is used to construct characteristic points, which makes it possible to calibrate the mismatches between pictures obtained during the rotation of a quarter-wave plate and a polarizer. Using this method a field with an array of PSs is measured. The experimental result is compared with the numerical simulation. We also carry out some data analysis. The comparison and analysis emphasize the necessity and feasibility of this method to measure the PSs.

Distributions of Amplitude and Phase Around C-points: Lemon, Mon-Star, and Star

“…(11) is a function of both amplitude and phase, which means sophisticated control over phase (or amplitude) is needed to generate Mon-Star. However, in previous studies aiming to generate PSs [8][9][10][11][12][13], there has been almost no purposeful control over amplitude and phase around C-points. More constraints on amplitude and phase also illustrate that there exists a smaller probability to generate Mon-Star than Lemon in experiments.…”

“…6 by substituting    =-2π /3 and    =-π /3 into Eq. (12). In We know that the two conditions of Eqs.…”

“…These PSs determine the distribution of polarization ellipses around them, such as how in nonparaxial fields the major axes (minor axes) of polarization ellipses surrounding C-points are shown to form Möbius strips [3][4][5], while in paraxial fields polarization ellipses around C-points produce interesting structures named Lemon, Mon-Star, and Star [2,6]. Experiments have been successful in generating PSs [7][8][9][10][11][12][13], but generation of PSs with a desired shape or structure, especially generation of a Mon-Star, is still a challenge. This is because the distributions of amplitude and phase around C-points are complex and have not been developed clearly.…”