Wave Deflection and Shifted Refocusing in a Medium Modulated by a Superluminal Rectangular Pulse

Abstract: We explore the problem of scattering in a medium modulated by a superluminal rectangular pulse, with the pulse modulation realized through transverse excitations. We solve this problem in the moving frame where the modulation appears purely temporal, since the solution to a purely temporal modulation is known. Upon this basis, we use a graphical approach to find the angle and frequency of the wave scattered by the modulation under oblique incidence. This study reveals that superluminal modulations deflect plane waves retro-directively, and refocus cylindrical waves to a shifted point of space with respect to the original source.