Unfolding the multivalued planar waveguide dispersion relation

Conventional 2*2 matrix techniques give an implicit dispersion relation for planar waveguides that involves multivalued functions. This multivalued form can cause complications and confusion. It is shown that it is possible to derive a single-valued form that avoids all such difficulties. The resulting formulation allows the unique identification of all the proper and improper modes of a structure and simplifies their numerical determination.<
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