We study GaN-based light emitting diodes incorporating an omnidirectional photonic crystal with Archimedean lattice. Photonic bands are observed over several Brillouin zones, revealing reciprocal space symmetries and evidencing the omnidirectionality of the photonic crystal. Intensities of the diffracted bands are found to agree with the Fourier transform of the crystal lattice, and confirm its Archimedean nature. (c) 2006 American Institute of Physics.