Characteristics of five-layer planar dielectric waveguides

Eight types of five-layer planar dielectric waveguides for the optical wavelength range are analyzed to show that the use of an additional (second) cladding makes it possible to construct single-mode waveguides of large transverse dimensions. Higher stray modes are strongly suppressed (filtered off) by deliberately induced heat or radiation losses. A negative waveguide dispersion partly compensates the positive dispersion of the waveguide material. Signal distortions are estimated for single-mode and multimode operation of these waveguides.