  Inverse design in photonics has gathered increasing attention as a powerful
approach that goes beyond the intuition-based designs. In this Letter, we
present the inverse design and experimental demonstration of compact optical
cloaks at microwave frequencies is conducted. Two different configurations of
rectangular and circular cloaks are numerically designed to reduce the
scatterings of incident light interacting with a perfect electrical conductor
object. The designed cloaking structures consist of dielectric polylactide
material with a low refractive index and they are fabricated by 3D printing
approach. The experimental measurements are in good agreement with the
numerical calculations. The designed region covering (4{\lambda} x 4{\lambda})
area enables hiding circular object of {\lambda} diameter where {\lambda}
denotes the wavelength of incident light. The proposed approach may enable the
concealment of different objects possessing various size and shapes.

Applied Physics