OPTIMAL-DESIGN USING STRATIFIED BIANISOTROPIC MEDIA - APPLICATION TO ANTIREFLECTION COATINGS

A frequency-domain optimal design problem using a stratified bianisotr opic slab is considered. An optimization approach is used to determine the constitutive parameters as functions of the position so that a ce rtain desired reflection- and transmission-pattern are achieved. It is based on a gradient method, where the gradients are calculated explic itly. To control the spatial variation of the attained parameter profi les, parameters and gradients are expanded in a truncated set of ortho gonal basis functions with support over the entire width of the slab. The design algorithm is tested numerically on a minimal reflection pro blem, where stratified uniaxial chiral-omega slabs coated on perfect c onductors are optimized to minimize the reflected power in a certain f requency-band. Numerical results indicate that uniaxial omega media is an appropriate choice for anti-reflection coatings.