Recent advances in the field of guided-wave optics, such as fiber optics and integrated optics, have included the introduction of arbitrarily-shaped optical waveguides which, in many cases, also happened to be arbitrarily inhomogeneous, dissipative, anisotropic, and/or nonlinear. Most of such cases of waveguide arbitrariness do not lend themselves to analytical so- lutions; hence, computational tools for modeling and simulation are es- sential for successful design, optimization, and realization of the optical waveguides. For this purpose, various numerical techniques have been de- veloped....