Path-independent insertion loss optical space switch

Optical space switches are basic components in both optical space-division and optical time-division switching networks. The maximum size of optical space switches is limited by both Increases In insertion loss and crosstalk at each switch element, e.g., a directional coupler in Ti:LiNbO3, in the worst path. Several space switch structures with low insertion loss and low crosstalk have been reported,1–3 but their properties are obtained by doubling the total number of switch elements.