Low-crosstalk 1*2 optical switch composed of twisted nematic liquid crystal cells

A low-crosstalk structure for a 1*2 optical switch using twisted nematic liquid crystal (TN-LC) cells is proposed. Low crosstalk can be obtained by using a walkoff polarizing beam splitter between two TN-LC cells mutually controlled in opposite states. A 1*2 polarization-independent optical switch is assembled using single-mode fibers. Its insertion loss and crosstalk, in both switching modes, are >