  The ability to construct large photonic cluster states capable of supporting
universal quantum computation relies on fusing together cluster primitives.
These fusion operations are probabilistic and the efficiency of the
construction process relies on recycling remains of cluster primitives that
have undergone failed fusion attempts. Here I consider the effects of the
inevitible decoherence that must arise while storing cluster primitives. First,
I explore the case where dephased two-qubit cluster states are the basic
resource for the construction of all larger cluster states, all fusion
operations are successful, and no further dephasing occurs during the
construction process. This allows us to explore how decoherence of the most
basic, primitive clusters translate into imperfections of the larger cluster
states constructed from them. I then assume that decoherence occurs before
every attempted fusion operation and determine the best way to build a five
qubit cluster. This requires including the effects of the fusion operation
failures. Fidelity is used as the measure of accuracy for the constructed
cluster states. Finally, I include a short discussion of photon loss and how it
affects the construction of simple photonic clusters.
