US Patent 7840100 Devices for dispersion compensation, beam displacement, and optical switching

A method of laterally displacing at least a component of a light beam, the method comprising: a) directing the beam to enter a block of birefringent material at a first location, and at least the component of the beam to pass through the block on a first path to an exit location; and b) changing a polarization of the component of the beam after it has passed through the block, and directing it to pass back through the block from the previous exit location to a next exit location, following a next path oriented at changed angle due to its changed polarization state, at least one time; the component of the beam thereby being laterally displaced from the first location, when it exits the block a last time.