Coupled power theorem and orthogonality relations for optical disk waveguides

A coupled power theorem is developed which is applied to radial line (disk) optical dielectric waveguides. This theorem is utilized to develop transverse-electric and transverse-magnetic orthogonality relations for modes propagating in perfect disk guides. Because azimuthal variation is easily controlled, the disk guide can be employed as a device for coupling energy from a single source to a large number of optical fiber guides.