CMP Weekly Seminars

Jiangfeng Zhou - Study of left handed materials   Room 5 Physics, 2008-09-04 16:10:00 - 2008-09-04 17:00:00

Left handed materials (LHMs) are artificial materials that have negative electric permitivity, negative magnetic permeability, and negative index of refraction across a common frequency band. They possess EM properties not found in nature. LHMs have attracted tremendous attention because of their potential applications to build the perfect lens and cloaking devices. Recently, researchers are trying hard to push the operating frequency of LHMs from microwave frequency into terahertz and the optical regime. We investigate numerically the limits of the magnetic resonant response with negative effective permeability, for realistic LHM designs from microwave frequencies up to optical frequencies. We find the breakdown of linear scaling due to the free electron kinetic energy for resonances above 100 THz. Due to this breakdown property, much smaller structure size of LHMs deign is required, so new designs with simpler topology are needed for the optical regime. We investigated a short wire pair design that could be used to build LHMs at the optical regime. Chiral metamaterials provide an alternative approach to realize the negative refractive index. We studied a double layer rosette design and demonstrated the negative refractive index experimentally at microwave frequency.