Abstract

Many devices have been demonstrated that are not accurately modeled by using only bound eigenmodes. The role of the non-bound fields in these models can go beyond simply representing radiative losses, for example: coherent superposition of radiation modes can produce slowly decaying behavioral] radiation modes can be excited and then coupled back into the device,[2] inclusion of radiation modes can be critical for accurate calculations of power in absorbing structures,[3] and radiation modes can influence the calculation of reflection at interfaces. Consequently, there has been an increased interest in eigenmode expansion techniques that include these radiation fields. The two most popular means of appending the radiation field to the bound waveguide mode expansion are the improper "leaky" mode techniquefl] and the sampling of the radiation field by means of an imposed boundary (such as a metal wall).[2]

© 1993 Optical Society of America