A new reconstruction algorithm for dielectric cylinders using FDTD and design sensitivity analysis

We propose a novel algorithm to reconstruct the profile of unknown dielectric objects by using the FDTD technique and design sensitivity analysis (DSA). By introducing the DSA and the adjoint variable method, we can exactly calculate the derivative of the error function with respect to the dielectric variable, and reduce the computational costs. The proposed method is validated by applying it to the reconstruction of unknown 2D dielectric profiles which are illuminated by TM/sup z/ plane waves with a Gaussian pulse.