Multilayer optical waveguides with higher dielectric losses in the central layer

An analysis is made of the waveguide characteristics of three types of planar multilayer optical waveguide consisting of a central layer (core) and two claddings. The results are used to show that the use of a core material with higher dielectric losses may ensure effective filtering of higher modes at the expense of a slight increase in the attenuation of lower modes. If the transverse dimensions are relatively large, these waveguides have characteristics similar to those of single-mode waveguides.