Lightwave Engineering

5	Guided Wave Optics

Optical waveguiding means confining light from a light source to a medium with a nearly uniform structure in the direction of propagation and then guiding it to a target region. This medium is called an optical waveguide, and the axis of the direction of propagation is called the optical axis. Although a spatially localized electromagnetic wave (in other words, a beam wave) has the property wherein it spreads by diffraction, the light diverging from the optical axis, as it propagates inside the optical waveguide, is pulled back to the direction of the optical axis because of reflection and refraction and is confined in the core thus waveguided. A transparent medium (dielectric materials and semiconductors with band gap ...