Abstract: The invention relates to an optical circulator for use as a front end for an optical device platform, which requires a pair of like-polarized sub-beams as input. A combined beam of light comprising a plurality of wavelength channels is input the optical circulator at an input port, and the pair of like-polarized sub-beams is launched via a pair of input/output ports into the optical device platform, wherein the sub-beams are modified. Within the optical device platform the combined beam of light is separated into individual channels, and one or more of the channels can be dropped or attenuated before the remaining channels are recombined into to modified sub-beams for output. The two modified sub-beams are launched back into the optical circulator, which directs the modified sub-beams to an output port remote from the input port. Any light reentering the optical circulator with the wrong polarization will neither exit the input nor the output port.

Abstract: The invention relates to an optical circulator for use as a front end for an optical device platform, which requires a pair of like-polarized sub-beams as input. A combined beam of light comprising a plurality of wavelength channels is input the optical circulator at an input port, and the pair of like-polarized sub-beams is launched via a pair of input/output ports into the optical device platform, wherein the sub-beams are modified. Within the optical device platform the combined beam of light is separated into individual channels, and one or more of the channels can be dropped or attenuated before the remaining channels are recombined into to modified sub-beams for output. The two modified sub-beams are launched back into the optical circulator, which directs the modified sub-beams to an output port remote from the input port. Any light reentering the optical circulator with the wrong polarization will neither exit the input nor the output port.

Abstract: The invention provides an optical circulator having a plurality of ports, a non-reciprocal rotator, a beam shifter means in the form of at least one birefringent crystal, a polarization rotator, and a reflector. The plurality of ports is sequentially aligned at one end of the device, while the reflector is disposed at an opposite end. First and second lenses provide efficient coupling between the plurality of ports, in combination with the reflector. Conveniently, the beam shifter provides the beam displacement necessary to switch between successive ports, while simultaneously minimizing the size requirements of the other optical components.