On the relation between passive optical fiber component properties and the network configuration

For some years now passive optical-fiber components have been available which are mainly based on the directional and star coupler as made in the biconical taper (BT) technique. The network configurations possible are restricted by the types of component available. In the fused-head-end (FHE) technique these as well as other types of components can be made which may give rise to different possible network configurations.