  We study photon localisation and delocalisation in a system of two nonlinear
cavities with intensity-dependent coupling. It is shown that complete
localisation or delocalisation is possible for proper choices of the strengths
of nonlinearity, detuning and inter-cavity coupling. Role of the relative phase
in the initial superposition in attaining localisation and delocalisation is
discussed. Effects of dissipation and decoherence are considered and the use of
quantum interference in reducing dissipation is explored. Many of the features
of the system are shown to be the consequences of quantum interference.
