Two-dimensional local density of states in two-dimensional photonic crystals

We calculate the two-dimensional local density of states (LDOS) for two-dim ensional photonic crystals composed of a finite cluster of circular cylinde rs of infinite length. The LDOS determines the dynamics of radiation source s embedded in a photonic crystal. We show that the LDOS decreases exponenti ally inside the crystal for frequencies within a photonic band gap of the a ssociated infinite array and demonstrate that there exist "hot" and "cold" spots inside the cluster even for wavelengths inside a gap, and also for wa velengths corresponding to pass bands. For long wavelengths the LDOS exhibi ts oscillatory behavior in which the local density of states can be more th an 30 times higher than the vacuum level. (C) 2001 Optical Society of Ameri ca.