The photonic band gap (PBG) effect on the fluorescence lifetime of molecules in three–dimensional colloidal photonic crystals is studied theoretically by means of a full vectorial quantum electrodynamics. In these colloidal systems where the refractive index contrast is as low as below 1.2, the PBG-induced lifetime variation is found to be below $5\%.$ Our theoretical simulations can help to distinguish the pure PBG effect on the observed fluorescence lifetime variation from other effects such as complex electronic and chemical interactions that can occur in condensed-matter materials.

• Received 12 June 2000

DOI:https://doi.org/10.1103/PhysRevB.63.125106