Abstract: 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.

Abstract: 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.

Abstract: This application describes an optical switching method for selectively directing an input beam to at least one of two output channels. The input beam impinges on a polarizing beam splitting surface, splitting the input beam into two beam components of different polarizations propagating along different optical paths. These beam components then pass through a controllable polarization rotating medium which selectively affects the polarization of each of the beam components. The beam components are then directed back onto the polarizing beam splitting surface again, producing at least one output beam which propagates toward at least one selected output channel, depending on the state of the medium. The polarizing beam splitting surface is fabricated on a block of the controllable polarization rotating medium, and the input beam also passes through the medium before being split into two beam components by the polarizing beam splitting surface.

Abstract: A method of in-channel estimation of the OSNR of an optical signal comprising a series of transmitted data units, each data unit having one of a discrete set of different amplitudes, the method comprising: