Firstly,the structure and optical realization of non-blocking Clos(2,4,2) optical network are discussed in detail.Secondly,novel 1×2,2×2 and 2×4 optical switched are proposed with conventional polarization controlling technology by using phase spatial-light modulator(PSLM),polarized beam splitter(PBS) and reflective mirror,which will be used to realize the non-blocking Clos(2,4,2)optical network.Simultaneously,the upgrading capacity of n×moptical switch is also discussed.Finally,according to the...