Compact polarization dependent optical switching units

Abstract

A compact optical switching unit includes a spatial light modulator coupled to a delay assembly such that incident light beams are respectively selectively directed along either a direct path or a delay path dependent on the linear polarization of the light beam. The delay assembly includes a light deflection device, such as a polarizing beam splitter, coupled to a delay path apparatus, such as mirror prisms or fiber optic cable. A compact and readily fabricated cascade of optical switching units includes polarizing beam splitter blocks and polarization rotation switch blocks, a portion of which constitutes the polarizing beamsplitters and spatial light modulators in respective optical switching units sequentially optically coupled. Delay path apparatuses disposed along an axis orthogonal to both the axis of beams passing along a direct path through polarizing beam splitter switches on the direct path and the axis between respective optical switching units result in a compact optical architecture.