Patent ID: 6360037
Filing Date: 2002-03-19
Classification: G02B,G02F

Abstract:
An optical switching module for selectively switching a light beam entering a first input port between first and second output ports, said modules comprising:an optical circulator having a unidirectional input port, a unidirectional output port and a bi-directional port; a beam displacing prism optically aligned with said bi-directional port of said circulator, said prism being arranged to separate light exiting said bi-directional port into a p-polarized beam and an s-polarized beam; polarization control means having a first mode for receiving and passing input light such that a polarization of said input light is unchanged and having a second mode for changing the polarization of said input light by 90Â°, said control means being aligned with said prism for changing polarization of one of said p-polarized and s-polarized beams to form a pair of beams with common polarization; a polarization beam splitter for passing input light of a first polarization along a first path and for reflecting input light of a second polarization along a second path, said beam splitter being optically aligned with said polarization control means; an internal reflection prism optically aligned in said second path for reflecting light back into said beam splitter whereby light having said second polarization is directed in a reverse direction through said beam splitter, passing back through said polarization control means and recombining in said beam displacing prism to enter said bi-directional port of said circulator through said circulator and be directed out of said unidirectional output port; and said light of the first polarization being directed through said beam splitter to said second output terminal.