This in-depth work explains how transverse optical waveguide geometry influences field distribution and polarization properties. You will gain a thorough understanding of the fundamental physics of mode structure. covers single- and few-mode optical waveguides with an emphasis on single-core and multicore optical fibers and couplers, including a large range of geometries and anisotropies. Analysis is performed using extensions of the weak-guidance perturbation formalism together with elementary group representation theory. This definitive volume offers a detailed introduction to and classification of diverse forms of fundamental and higher-order modes and various polarization manifestations. Coverage includes: