We propose a novel numerical approach for the optimal design of wide-areaheterogeneous electromagnetic metasurfaces beyond the conventionally usedunit-cell approximation. The proposed method exploits the combination ofRigorous Coupled Wave Analysis (RCWA) and global optimization techniques (twoevolutionary algorithms namely the Genetic Algorithm (GA) and a modified formof the Artificial Bee Colony (ABC with memetic search phase method) areconsidered). As a specific example, we consider the design of beam deflectorsusing all-dielectric nanoantennae for operation in the visible wavelengthregion; beam deflectors can serve as building blocks for other more complicateddevices like metalenses. Compared to previous reports using local optimizationapproaches our approach improves device efficiency; transmission efficiency isespecially improved for wide deflection angle beam deflectors. The ABC methodwith memetic search phase is also an improvement over the more commonly used GAas it reaches similar efficiency levels with upto 35% reduction in computationtime. The method described here is of interest for the rapid design of a widevariety of electromagnetic metasurfaces irrespective of their operationalwavelength.
展开▼
