OPTIMAL-DESIGN OF MINIMALLY REFLECTIVE COATINGS

The problem of determining coatings on a flat surface that produces th e least amount of wave reflection when it is struck by a known inciden t pulse is investigated. A departure from previous work on this subjec t is that the problem is formulated in the time domain, leading to a m ore intuitive understanding of the wave cancellation phenomenon. The m odel problem considered in this work is that of a scalar, plane wave p ropagation. The resulting optimization problem is analyzed in the regi me where impedance contrasts between the coatings are small. We show t hat the problem may be illposed, depending on the nature of the incide nt pulse. We propose a regularization strategy and an efficient comput ational scheme for solving the optimization problem. The design proble m is further studied in several numerical experiments.