Spatial distribution of the emission intensity in a photonic crystal: Self-interference of Bloch eigenwaves

The analysis of an angular distribution of the emission intensity of a two-level atom (dipole) in a photonic crystal reveals an enhancement of the emission rate in some observation directions. Such an enhancement is the result of the bunching of many Bloch eigenwaves with different wave vectors in the same direction due to the crystal anisotropy. If a spatial distribution of the emission intensity is considered, the interference of these eigenwaves should be taken into account. In this paper, the far-field emission pattern of a two-level atom is discussed in the framework of the asymptotic analysis the classical macroscopic Green function. Numerical example is given for a two-dimensional square lattice of air holes in polymer. The relevance of results for experimental observation is discussed.