Optical fiber is a form of dielectric waveguide used at optical wavelengths. Dielectric resonators are pieces of dielectric material inserted into the waveguide. An example of an optical waveguide is optical fiber. Multiple quantum wells improve the overlap of the gain region with the optical waveguide mode. Electromagnetic pulses transmitted by lightning strikes propagate within that waveguide. Schemes are generally grouped into two categories&colon; material dispersion and waveguide dispersion. Coaxial cable may be viewed as a type of waveguide. Transverse modes occur because of boundary conditions imposed on the wave by the waveguide. S-parameters are used at frequencies where the ports are often coaxial or waveguide connections. In a waveguide, phase velocity varies with frequency. It used a dual tapered waveguide and revised speakers. This results in a step change in the characteristic impedance of the waveguide. Bose also invented waveguide and horn antennas for use in his experiments. A nanosized contact formed by electromigration acts like a waveguide for electrons. The easiest geometry to solve is the rectangular waveguide.