Far-infrared propagation in metal wire microstructures

Densely packed arrays (76% volume fraction) of 10 mu m diameter parallel indium wires exhibit an enhanced transmission, of similar to 10(3), relative to an indium foil of equal thickness for far-infrared (k < 80 cm(-1)) propagating along the wire length. The absorption increases as k(0.45 +/- 0.07)and is explained by the dynamic Maxwell-Garnett model, which includes eddy current dissipation. The effective surface conductivity is depressed fiftyfold with respect to the bulk. The implications for plasmons in metal wire microstructures and for developing simultaneously transmissive and conductive composites are discussed. (C) 1997 American Institute of Physics.