Abstract: The present invention provides a multi-functional separator which may be used as a demultiplexer or as a multiplexer in wavelength division multiplexed optical communication systems. The preferred embodiment of the multi-functional separator includes a first polarization beam splitter, a non-reciprocal rotator; a reciprocal rotator, a second polarization beam splitter, and a non-linear interferometer. Each of the polarizing input and polarizing output ports includes an optical fiber, a collimator, a birefringent walk-off plate and a non-reciprocal optical rotator. The collimator includes a glass plate and a lens/spacer element between the glass plate and the birefringent walk-off plate. The multi-functional separator is easily aligned by adjusting the positions of each of the polarizing input and output port. Further embodiments of the present invention provide additional optical isolation, optical circulation, optical comb filtering and/or two-stage channel separation capabilities.

Abstract: The present invention provides an improved optical collimator. The optical collimator includes: a glass plate including a first face and a second face opposite to the first face; and a lens/spacer element optically coupled to the second face of the first glass plate. The lens/spacer element includes: a basal surface coupled to the second face of the glass plate, a lens optically coupled to the second face of the glass plate and coupled to the basal surface, a top surface opposite to the basal surface, and a first and a second side walls each coupled to the basal surface and the top surface. The present invention facilitates physical alignment and proper spacing relative to optical fibers and optical components, provides a simple means for constructing linear and two-dimensional arrays of collimators, and leads to improved utilization of space, decreased fabrication cost, and increased system-level yield.

Abstract: The present invention provides a multi-functional separator which may be used as a demultiplexer or as a multiplexer in wavelength division multiplexed optical communication systems. The preferred embodiment of the multi-functional separator includes a first polarization beam splitter, a non-reciprocal rotator; a reciprocal rotator, a second polarization beam splitter, and a non-linear interferometer. Each of the polarizing input and polarizing output ports includes an optical fiber, a collimator, a birefringent walk-off plate and a non-reciprocal optical rotator. The collimator includes a glass plate and a lens/spacer element between the glass plate and the birefringent walk-off plate. The multi-functional separator is easily aligned by adjusting the positions of each of the polarizing input and output port. Further embodiments of the present invention provide additional optical isolation, optical circulation, optical comb filtering and/or two-stage channel separation capabilities.