title: Polarization singularities in optical lattices.
abstract: Polarization singularities are shown to be unavoidable features of three-dimensional optical lattices. These singularities take the form of lines of circular polarization, C lines, and lines of linear polarization, L lines. The polarization figures surrounding a C line (L line) rotate about the line with winding number +/-1/2 (+/-1). C and L lines permeate the lattice, meander throughout the unit cell, and form closed loops. Surprisingly, every point in a linearly polarized optical lattice is found to be a singularity about which the surrounding polarization vectors rotate with an integer winding number.
authors.affiliation: Deportment of Physics, Bar-Ilan University, Ramat-Gan 52900, Israel. freund@mail.biu.ac.il
authors.forename: Isaac
authors.initials: I
authors.lastname: Freund