TRANSFER-MATRIX OF A DIRAC-LIKE SINGULARITY OF THE DIELECTRIC PERMITTIVITY

We derive the general expression, for TE-polarization, of the transfer matrix associated to a Dirac-like singularity of the dielectric permi ttivity. We show that this approach is successful in modeling quantum wells, as well as localized loss centers used for the ''modal sculptur ing'' in semiconductor lasers, Its range of validity includes any disc ontinuity of finite length as long as its actual extension remains muc h inferior to the optical wavelength.