Optical Mobius strips in three dimensional ellipse fields: II. Lines of linear polarization

The minor axes of, and the normals to, the polarization ellipses that surround singular lines of linear polarization in three dimensional optical ellipse fields are shown to be organized into Mobius strips (technically twisted ribbons) and into structures we call "rippled rings" (r-rings). The Mobius strips have two full twists, and can be either right- or left-handed. The major axes of the surrounding ellipses generate cone-like structures. Three orthogonal projections that give rise to 15 indices are used to characterize the different structures These indices, if independent, could generate 839,808 geometrically and topologically distinct lines: selection rules are presented that reduce the number of lines to 8248, some 5562 of which have been observed in a computer simulation. Analytical expressions are presented for 11 of the 15 indices in terms of wavefield parameters; four indices proved to be intractable. Statistical probabilities are presented for the most important index combinations in random fields. It is argued that it is presently feasible to perform experimental measurements of the Mobius strips, r-rings, and cones described here theoretically, (C) 2009 Elsevier B.V. All rights reserved.