On the crucial role of impedance matching in chirolens design

It is shown that impedance matching delivers two specific benefits for chirolens design. First, there is no left‐handed ↔ right‐handed field conversion inside a nonhomogeneous chirolens with a spatially constant impedance. Second, when the chirolens is impedance matched to the surrounding free space, the incident, the scattered and the internally induced fields have the same handedness. In addition, the backscattered field of an impedance‐matched, radially non‐homogeneous, spherical chirolens is null in the far zone.