Electromagnetic absorption in anisotropic photonic crystal of alumina cylinders

[EN] We present a theoretical and experimental study of the effective permittivity of a photonic crystal (PC) made of parallel dielectric rods in the long-wavelength limit. Using the plane-wave expansion method we derive an analytical expression for the imaginary part of the dielectric tensor. Angular dependence of the dissipative part of permittivity turns out to be more complicated than that for the real part. In particular, it exhibits stronger anisotropy for a PC with rectangular unit cell. Theoretical and numerical results are compared to the experimental measurements of microwave reflection and transmission through a PC fabricated from low-loss alumina rods. A good agreement between the theory and experiment was obtained in the limit where the effective medium approximation is valid. © 2011 Elsevier B.V.
This work was supported by the Ministerio de Ciencia e Innovación of Spain under contracts TEC 2007-67239, TEC 2010-19751 and CONSOLIDER CSD2008-00066, by the US Department of Energy through the Grant No. DE-FG02-06ER46312, and by the Office of Naval Research through the Grant No. 000140910554. L.G. acknowledges the support by CONACyT (Mexico) and A.K. acknowledges the support by the Ministerio de Educación of Spain Contract No. SAB2009-00009. Authors thank F. Cervera for technical help.