4Ã\x974 Optical Switch with Polarization Selective Elements

The basic optical switch in optical interconnection networks is a 2×2 optical switch which provides two switching states: the "straight" state and the "swap" state. Several kinds of optical switch have been presented such as polarization selective elements combined with electro-optic halfwave plates. Using these basic optical switches to construct a 4×4 nonblocking interconnection network, such as Benes network and double-layer network, needs three stages of optical switches. In this presentation, a 4×4 optical switch with polarization selective elements and electro-optic halfwave plates will be proposed. In this switch, the control configurations of electro-optic halfwave plates have been changed to support all switching states of polarization selective elements. Compared with 4×4 nonblocking interconnection networks, this 4×4 optical switch has the lowest system insertion loss and the fewest required components. Its structure and connection path for different switching functions will be discussed in detail.