Abstract
As a preparatory study of electromagnetic pulse propagation in open waveguides, the modes of propagation of pulses in open slab waveguides are investigated systematically. Core and cladding both consist of simple (linear, homogeneous, isotropic), dispersive materials modeled by temporal convolution with physically sound susceptibility kernels. Under these circumstances, pulses cannot propagate along the guide unless the sum of the (first) initial derivatives of the electric and magnetic susceptibility kernels of the medium in the core is less than the corresponding sum for the medium in the cladding. Only a finite number of pulse modes can be excited, and relevant temporal Volterra integral equations of the second kind for these modes are derived.