Dielectric Rectangular Waveguide and Directional Coupler for Integrated Optics

Proposals have been made for dielectric waveguides capable of guiding beams in integrated optical circuits very much as waveguides and coaxials are used for microwave circuitry.1-3 Figure 1 shows the basic geometries for these waveguides. The guide is a dielectric rod of refractive index n immersed in another dielectric of slightly smaller refractive index n ( l -- A ) ; both are in contact with a third dielectric which may be air (Fig. la) or a dielectric of refractive index n(l -- A), 2071 2096 T H E BELL SYSTEM TECHNICAL JOURNAL, SEPTEMBER AIR 1)9 10 Fig. 1 -- Dielectric waveguides for integrated optical circuitry.