Collective optical behavior in complementary wire arrays with Au nanoparticles

Collective optical properties emerge from complementary wire arrays, as determined by using the FTIR (Fourier transform infra-red) spectroscopy. Babinet's effect is clearly observed in the complementary patterns of the wire grating. Such patterns demonstrate the transmittance-enhanced behavior because of surface plasmon resonance of gold (Au) nano-particles on the top pattern surface. Unlike in conventional optical element fabrication, advanced integrated circuit (IC) processing technology is adopted to prepare our complementary pattern samples on a silicon (Si) wafer, and nano-gold-particles are used as the wire conductor in those patterns. The positive pattern is a sample patched with periodic Au wires on the Si wafer. The negative pattern is the adopted as the reverse of the positive pattern; the wire part is empty of Au but the surrounding space is filled with Au particles. This work supports the development of multi-functional optical components integrated in nano-scale semiconductor devices.