Speaker: Eric Plum
Date: 17/3/2010
Time: 2pm
Venue: B53 Seminar Room
Abstract:
Metamaterials are artificial media with unique electromagnetic properties engineered through structuring on the sub-wavelength scale. After a general introduction to the field of metamaterials, their potential will be illustrated using chirality-related phenomena.
It is well-known that intrinsically 3D-chiral materials (helices) show optical activity, i.e. rotation of the polarization state of light.
Recently it was discovered that also 2D-chiral patterns (flat spirals) lead to a fundamental electromagnetic effect: asymmetric transmission.
Key results presented here include (i) the first demonstration of a negative refractive index due to 3D chirality, (ii) the observation of giant optical activity in the first stereometamaterial, (iii) the first demonstration of optical activity in non-chiral metamaterials and (iv) the discovery of asymmetric transmission at non-chiral interfaces. The latter two findings are related to extrinsic chirality of the experimental arrangement, rather than intrinsic chirality of the material itself.