Enhanced directional scattering by core-shell microspheres

Highly directional scatterers are designed using core-shell microspheres. Their structural parameters are optimized analytically by genetic algorithm to optimize directional scattering, and the results are verified by finite difference time domain calculations. Using such optimized directional scatterers, the front-to-back ratio and directivity of a dipole is enhanced to 9 and 4.4 respectively.