Dual-band infrared metallodielectric photonic crystal filters

We have designed a metallodielectric photonic crystal with planar metallic scatterers to produce high reflectance in both the 3-5 and 8-12 mu m atmospheric windows over a wide range of angles of incidence. We have fabricated similar crystals using photolithography with Al scatterers in a polymer dielectric medium and measured their optical transmission, confirming the results of our design simulations. A fabricated filter produced a reflection band with > 30 dB rejection and a fractional bandwidth of 0.38. Our results show that it is possible to fabricate infrared photonic crystal filters comparable in performance to those with thick metal elements, but with the ease of manufacture of thin metal layers. (C) 2000 American Institute of Physics. [S0003-6951(00)03040-0].