Adjoint waves as waves generated by a distributed source of a traveling wave
А. С. Раевский, С. Б. Раевский · Technical Physics Letters · 2013
We consider the waves in an isotropic two-layer guiding structure described by a boundary-value problem for the associated Helmholtz equation. It is shown that these waves are excited by the source of traveling waves and actually exist in a certain frequency range while being “attached” to this source.