Analytical Design of Additively Manufactured Focusing Metamaterial

Analytical effective refractive index (n
eff
) calculations for unit cells of ring/spoke structures, fabricated by two-photon polymerization, are undertaken. Geometrical parameters (spoke width, spoke length and number of spokes) are varied. Resulting n
eff
values are mapped to a hyperbolic-secant profile resulting in a gradient index optic.