Transient reflection from a multilayer with a time jump in the sublayer permittivities

A theoretical investigation of the wave reflection from a 1-D quasiperiodic dielectric multilayer with a transient permittivity of sublayers is presen ted. The problem of field interaction with such a structure is reduced to t he Volterra integral equations for the field in a transient medium, and is solved by convergent iterations. Numerical analysis shows a considerable mo difications of the reflected field spectrum. This modification depends on t he incident wave frequency, and can result in the appearance of not only ad ditional harmonics, but also a continuous spectrum over a wide waveband for some values of the incident wave frequency. Therefore, the considered time -varying structures provide rich opportunities for spectrum transformation. (C) 2001 John Wiley & Sons, Inc.