Experimental demonstration of reflection minimization at two-dimensional photonic crystal interfaces via antireflection structures

Abstract

We experimentally confirm that the antireflection structures effectively minimize unnecessary reflections of self-collimated microwave beams at the interfaces of a two-dimensional photonic crystal, which is composed of cylindrical alumina rods. Optimized design parameters for the antireflection structures are obtained from the one-dimensional antireflection coating theory and the finite-difference time-domain simulations. Measured transmittance through the photonic crystal samples with and without the antireflection structures agree well with the simulation results. The measured results show that the photonic crystal with an antireflection structure yields about 90% transmission of incident power on the average in the frequency range of 12.0 to 13.0 GHz. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3176949]